PHYL 141

1. Introduction

abdominal

relating to the abdomen, the superior portion of the abdominopelvic cavity

abdominal cavity

the space bounded by the abdominal walls, diaphragm, and pelvis

abdominopelvic cavity

division of the anterior (ventral) cavity that houses the abdominal and pelvic viscera

anatomical position

standard reference position used for describing locations and directions on the human body

anatomy

science that studies the form and composition of the body’s structures

anterior

describes the front or direction toward the front of the body; also referred to as ventral

anterior cavity

larger body cavity located anterior to the posterior (dorsal) body cavity; includes the serous membrane-lined pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as ventral cavity

atoms

the simplest form of matter that can be combined to make molecules

caudal

describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column); also referred to as inferior

cell

the basic structural unit of all organisms

cephalic

relating to the head

cervical

relating to the neck

control center

compares values to their normal range; deviations cause the activation of an effector

cranial

describes a position above or higher than another part of the body proper; also referred to as superior

cranial cavity

division of the posterior (dorsal) cavity that houses the brain

deep

describes a position farther from the surface of the body

diaphragm

the partition separating the thoracic cavity from the abdominal cavity

differentiation

process by which unspecialized cells become specialized in structure and function

distal

describes a position farther from the point of attachment or the trunk of the body

dorsal

describes the back or direction toward the back of the body; also referred to as posterior

dorsal cavity

posterior body cavity that houses the brain and spinal cord; also referred to the posterior body cavity

effector

organ that can cause a change in a value

etymology

the derivation of a word or word history

frontal plane

two-dimensional, vertical plane that divides the body or organ into anterior and posterior portions

gross anatomy

study of the larger structures of the body, typically with the unaided eye; also referred to as macroscopic anatomy

growth

process of increasing in size

homeostasis

steady state of body systems that living organisms maintain

inferior

describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column); also referred to as caudal

lateral

describes the side or direction toward the side of the body

macroscopic anatomy

study of the larger structures of the body, typically with the unaided eye; also referred to as gross anatomy

medial

describes the middle or direction toward the middle of the body

metabolism

sum of all of the body’s chemical reactions

microscopic anatomy

study of very small structures of the body using magnification

molecule

an organized structure of bonded atoms

movement

the change of position by an organism or part of organism, often in response to stimuli

negative feedback

homeostatic mechanism that tends to stabilize an upset in the body’s physiological condition by preventing an excessive response to a stimulus, typically as the stimulus is removed

normal range

range of values around the set point that do not cause a reaction by the control center

oblique plane

neither perpendicular nor parallel to a given line or surface; slanting; sloping

organ

functionally distinct structure composed of two or more types of tissues

organ system

group of organs that work together to carry out a particular function

organism

living being that has a cellular structure and that can independently perform all physiologic functions necessary for life

organization

the specific arrangement of atoms, molecules, cells, tissues and organs that define an organism

palmar

of, relating to, or located in or on the palm of the hand

parietal pericardium

the serous membrane lining the pericardial cavity

parietal peritoneum

the serous membrane lining the abdominal cavity

parietal pleura

the serous membrane lining the pleural cavities

pelvic cavity

the space bounded by the bones of the pelvis and pelvic girdle

pericardial cavity

the cavity encasing the heart

pericardium

sac that encloses the heart

peritoneum

serous membrane that lines the abdominopelvic cavity and covers the organs found there

physiology

science that studies the chemistry, biochemistry, and physics of the body’s functions

plantar

of or relating to the sole of the foot

plane

imaginary two-dimensional surface that passes through the body

pleura

serous membrane that lines the pleural cavity and covers the lungs

positive feedback

mechanism that intensifies a change in the body’s physiological condition in response to a stimulus

posterior

describes the back or direction toward the back of the body; also referred to as dorsal

posterior cavity

posterior body cavity that houses the brain and spinal cord; also referred to as dorsal cavity

prone

face down

proximal

describes a position nearer to the point of attachment or the trunk of the body

regulation

the process of maintaining a physiological equilibrium, see homeostasis

repetition

the practice of going through learning materials several times as part of the studying process

reproduction

process by which new organisms are generated

responsiveness

ability of an organisms or a system to adjust to changes in conditions

sagittal plane

two-dimensional, vertical plane that divides the body or organ into right and left sides

scientific method

the process of scientific discovery whereby observations lead to the formation of hypotheses, experiments are designed and performed, and data are compared to null hypotheses for drawing conclusions

section

in anatomy, a single flat surface of a three-dimensional structure that has been cut through

self-quizzing

the practice of testing oneself as part of the studying process

sensor

(also, receptor) reports a monitored physiological value to the control center

serosa

membrane that covers organs and reduces friction; also referred to as serous membrane

serous fluid

A lubricating fluid produced by and between folds of serous membrane

serous membrane

membrane that covers organs and reduces friction; also referred to as serosa

set point

ideal value for a physiological parameter; the level or small range within which a physiological parameter such as blood pressure is stable and optimally healthful, that is, within its parameters of homeostasis

superficial

describes a position nearer to the surface of the body

superior

describes a position above or higher than another part of the body proper; also referred to as cranial

supine

face up

thoracic

relating to the superior ventral cavity; the thoracic cavity

thoracic cavity

division of the anterior (ventral) cavity that houses the heart, lungs, esophagus, and trachea

tissue

an aggregate of similar cells and cell products forming a definite kind of structural material

transformation

to change from one form to another; as a study strategy this refers to the practice of transforming the information in narrative form to a diagram, flow chart or other illustration

transverse plane

two-dimensional, horizontal plane that divides the body or organ into superior and inferior portions

ventral

describes the front or direction toward the front of the body; also referred to as anterior

ventral cavity

larger body cavity located anterior to the posterior (dorsal) body cavity; includes the serous membrane-lined pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as anterior body cavity

visceral pericardium

the serous membrane covering the heart

visceral peritoneum

the serous membrane covering the abdominal cavity viscera

visceral pleura

the serous membrane covering the lungs

X-ray

form of high energy electromagnetic radiation with a short wavelength capable of penetrating solids and ionizing gases; used in medicine as a diagnostic aid to visualize body structures such as bones

2. Chemistry

acid

compound that releases hydrogen ions (H+) in solution

activation energy

amount of energy greater than the energy contained in the reactants, which must be overcome for a reaction to proceed

adenosine triphosphate (ATP)

nucleotide containing ribose and an adenine base that is essential in energy transfer

amino acid

building block of proteins; characterized by an amino and carboxyl functional groups and a variable side-chain

anion

atom with a negative charge

atom

smallest unit of an element that retains the unique properties of that element

atomic number

number of protons in the nucleus of an atom

base

compound that accepts hydrogen ions (H+) in solution

bond

electrical force linking atoms

buffer

solution containing a weak acid or a weak base that opposes wide fluctuations in the pH of body fluids

carbohydrate

class of organic compounds built from sugars, molecules containing carbon, hydrogen, and oxygen in a 1-2-1 ratio

catalyst

substance that increases the rate of a chemical reaction without itself being changed in the process

cation

atom with a positive charge

chemical energy

form of energy that is absorbed as chemical bonds form, stored as they are maintained, and released as they are broken

colloid

liquid mixture in which the solute particles consist of clumps of molecules large enough to scatter light

compound

substance composed of two or more different elements joined by chemical bonds

concentration

number of particles within a given space

covalent bond

chemical bond in which two atoms share electrons, thereby completing their valence shells

decomposition reaction

type of catabolic reaction in which one or more bonds within a larger molecule are broken, resulting in the release of smaller molecules or atoms

denaturation

change in the structure of a molecule through physical or chemical means

deoxyribonucleic acid (DNA)

deoxyribose-containing nucleotide that stores genetic information

disaccharide

pair of carbohydrate monomers bonded by dehydration synthesis via a glycosidic bond

disulfide bond

covalent bond formed within a polypeptide between sulfide groups of sulfur-containing amino acids, for example, cysteine

electron

subatomic particle having a negative charge and nearly no mass; found orbiting the atom’s nucleus

electron shell

area of space a given distance from an atom’s nucleus in which electrons are grouped

element

substance that cannot be created or broken down by ordinary chemical means

enzyme

protein or RNA that catalyzes chemical reactions

exchange reaction

type of chemical reaction in which bonds are both formed and broken, resulting in the transfer of components

functional group

group of atoms linked by strong covalent bonds that tends to behave as a distinct unit in chemical reactions with other atoms

hydrogen bond

dipole-dipole bond in which a hydrogen atom covalently bonded to an electronegative atom is weakly attracted to a second electronegative atom

inorganic compound

substance that does not contain both carbon and hydrogen

ion

atom with an overall positive or negative charge

ionic bond

attraction between an anion and a cation

isotope

one of the variations of an element in which the number of neutrons differ from each other

kinetic energy

energy that matter possesses because of its motion

lipid

class of nonpolar organic compounds built from hydrocarbons and distinguished by the fact that they are not soluble in water

macromolecule

large molecule formed by covalent bonding

mass number

sum of the number of protons and neutrons in the nucleus of an atom

matter

physical substance; that which occupies space and has mass

molecule

two or more atoms covalently bonded together

monosaccharide

monomer of carbohydrate; also known as a simple sugar

neutron

heavy subatomic particle having no electrical charge and found in the atom’s nucleus

nucleotide

class of organic compounds composed of one or more phosphate groups, a pentose sugar, and a base

organic compound

substance that contains both carbon and hydrogen

peptide bond

covalent bond formed by dehydration synthesis between two amino acids

periodic table of the elements

arrangement of the elements in a table according to their atomic number; elements having similar

properties because of their electron arrangements compose columns in the table, while elements having the same number of valence shells compose rows in the table

pH

negative logarithm of the hydrogen ion (H+) concentration of a solution

phospholipid

a lipid compound in which a phosphate group is combined with a diglyceride

phosphorylation

addition of one or more phosphate groups to an organic compound

polar molecule

molecule with regions that have opposite charges resulting from uneven numbers of electrons in the nuclei of the atoms participating in the covalent bond

polysaccharide

compound consisting of more than two carbohydrate monomers bonded by dehydration synthesis via

glycosidic bonds

potential energy

stored energy matter possesses because of the positioning or structure of its components

product

one or more substances produced by a chemical reaction

prostaglandin

lipid compound derived from fatty acid chains and important in regulating several body processes

protein

class of organic compounds that are composed of many amino acids linked together by peptide bonds

proton

heavy subatomic particle having a positive charge and found in the atom’s nucleus

purine

nitrogen-containing base with a double ring structure; adenine and guanine

pyrimidine

nitrogen-containing base with a single ring structure; cytosine, thiamine, and uracil

radioactive isotope

unstable, heavy isotope that gives off subatomic particles, or electromagnetic energy, as it decays; also called radioisotopes

reactant

one or more substances that enter into the reaction

ribonucleic acid (RNA)

ribose-containing nucleotide that helps manifest the genetic code as protein

solution

homogeneous liquid mixture in which a solute is dissolved into molecules within a solvent

steroid

(also, sterol) lipid compound composed of four hydrocarbon rings bonded to a variety of other atoms and molecules

substrate

reactant in an enzymatic reaction

suspension

liquid mixture in which particles distributed in the liquid settle out over time

synthesis reaction

type of anabolic reaction in which two or more atoms or molecules bond, resulting in the formation of a

larger molecule

triglyceride

lipid compound composed of a glycerol molecule bonded with three fatty acid chains

valence shell

outermost electron shell of an atom

3. Cells

active transport

form of transport across the cell membrane that requires input of cellular energy

amphipathic

describes a molecule that exhibits a difference in polarity between its two ends, resulting in a difference in water solubility

anaphase

third stage of mitosis (and meiosis), during which sister chromatids separate into two new nuclear regions of a dividing cell

anticodon

consecutive sequence of three nucleotides on a tRNA molecule that is complementary to a specific codon on an mRNA molecule

antioxidants

compounds that inhibit oxidation, a chemical reaction that can produce free radicals

carrier proteins

Membrane proteins that bind to a substrate and change its shape to transport the substrate across the membrane.

cell cycle

life cycle of a single cell, from its birth until its division into two new daughter cells

cell membrane

membrane surrounding all animal cells, composed of a lipid bilayer interspersed with various molecules; also known as plasma membrane

centriole

small, self-replicating organelle that provides the origin for microtubule growth and moves DNA during cell division

centromere

region of attachment for two sister chromatids

centrosome

cellular structure that organizes microtubules during cell division

channel protein

membrane-spanning protein that has an inner pore which allows the passage of one or more substances

chromatin

substance consisting of DNA and associated proteins

chromosome

condensed version of chromatin

cilia

small appendage on certain cells formed by microtubules and modified for movement of materials across the cellular surface

codon

consecutive sequence of three nucleotides on an mRNA molecule that corresponds to a specific amino acid

concentration gradient

difference in the concentration of a substance between two regions

cytokinesis

final stage in cell division, where the cytoplasm divides to form two separate daughter cells

cytoplasm

internal material between the cell membrane and nucleus of a cell, mainly consisting of a water-based fluid called cytosol, within which are all the other organelles and cellular solute and suspended materials

cytoskeleton

“skeleton” of a cell; formed by rod-like proteins that support the cell’s shape and provide, among other functions, locomotive abilities

cytosol

clear, semi-fluid medium of the cytoplasm, made up mostly of water

diffusion

movement of a substance from an area of higher concentration to one of lower concentration

DNA polymerase

enzyme that functions in adding new nucleotides to a growing strand of DNA during DNA replication

DNA replication

process of duplicating a molecule of DNA

electrical gradient

difference in the electrical charge (potential) between two regions

endocytosis

import of material into the cell by formation of a membrane-bound vesicle

endomembrane system

a group of membranes and organelles in eukaryotic cells that works together to modify, package, and transport lipids and proteins

endoplasmic reticulum (ER)

cellular organelle that consists of interconnected membrane-bound tubules, which may or may not be associated with ribosomes (rough type or smooth type, respectively)

exocytosis

export of a substance out of a cell by formation of a membrane-bound vesicle

extracellular fluid (ECF)

fluid exterior to cells; includes the interstitial fluid, blood plasma, and fluid found in other reservoirs in the body

facilitated diffusion

diffusion of a substance with the aid of a membrane protein

flagellum

appendage on certain cells formed by microtubules and modified for movement

G0 phase

phase of the cell cycle, usually entered from the G1 phase; characterized by long or permanent periods where the cell does not move forward into the DNA synthesis phase

G1 phase

first phase of the cell cycle, after a new cell is born

G2 phase

third phase of the cell cycle, after the DNA synthesis phase

gene

functional length of DNA that provides the genetic information necessary to build a protein

gene expression

active interpretation of the information coded in a gene to produce a functional gene product

genome

entire complement of an organism’s DNA; found within virtually every cell

glycoprotein

protein that has one or more carbohydrates attached

Golgi apparatus

cellular organelle formed by a series of flattened, membrane-bound sacs that functions in protein modification, tagging, packaging, and transport

homologous

describes two copies of the same chromosome (not identical), one inherited from each parent

hydrophilic

describes a substance or structure attracted to water

hydrophobic

describes a substance or structure repelled by water

hypertonic

describes a solution concentration that is higher than a reference concentration

hypotonic

describes a solution concentration that is lower than a reference concentration

integral protein

membrane-associated protein that spans the entire width of the lipid bilayer

intermediate filament

type of cytoskeletal filament made of keratin, characterized by an intermediate thickness, and playing a role in resisting cellular tension

interphase

entire life cycle of a cell, excluding mitosis

interstitial fluid (IF)

fluid in the small spaces between cells not contained within blood vessels

intracellular fluid (ICF)

fluid in the cytosol of cells

isotonic

describes a solution concentration that is the same as a reference concentration

kinetochore

region of a centromere where microtubules attach to a pair of sister chromatids

lysosome

membrane-bound cellular organelle originating from the Golgi apparatus and containing digestive enzymes

messenger RNA (mRNA)

nucleotide molecule that serves as an intermediate in the genetic code between DNA and protein

metaphase

second stage of mitosis (and meiosis), characterized by the linear alignment of sister chromatids in the center of the cell

metaphase plate

linear alignment of sister chromatids in the center of the cell, which takes place during metaphase

microfilament

the thinnest of the cytoskeletal filaments; composed of actin subunits that function in muscle contraction and cellular structural support

microtubule

the thickest of the cytoskeletal filaments, composed of tubulin subunits that function in cellular movement and structural support

mitochondrion

one of the cellular organelles bound by a double lipid bilayer that function primarily in the production of cellular energy (ATP)

mitosis

division of genetic material, during which the cell nucleus breaks down and two new, fully functional, nuclei are formed

mitotic spindle

network of microtubules, originating from centrioles, that arranges and pulls apart chromosomes during mitosis

mutation

change in the nucleotide sequence in a gene within a cell’s DNA

nuclear envelope

membrane that surrounds the nucleus; consisting of a double lipid-bilayer

nuclear pore

one of the small, protein-lined openings found scattered throughout the nuclear envelope

nucleolus

small region of the nucleus that functions in ribosome synthesis

nucleus

cell’s central organelle; contains the cell’s DNA

organelle

any of several different types of membrane-enclosed specialized structures in the cell that perform specific functions for the cell

osmosis

diffusion of water molecules down their concentration gradient across a selectively permeable membrane

oxidative stress

a phenomenon caused by an imbalance between production and accumulation of oxygen reactive species (ROS) in cells

passive transport

form of transport across the cell membrane that does not require input of cellular energy

peripheral protein

membrane-associated protein that does not span the width of the lipid bilayer, but is attached peripherally to integral proteins, membrane lipids, or other components of the membrane

peroxisome

membrane-bound organelle that contains enzymes primarily responsible for detoxifying harmful substances

phagocytosis

endocytosis of large particles

phospholipid bilayer

membrane made out of two layers of phospholipids

pinocytosis

endocytosis of fluid

plasma membrane

See definition for cell membrane

polypeptide

chain of amino acids linked by peptide bonds

promoter

region of DNA that signals transcription to begin at that site within the gene

prometaphase

the phase of mitosis following prophase and preceding metaphase, characterized by disappearance of nuclear envelop and the appearance of mitotic spindle and kinetochores at the centromeres.

prophase

first stage of mitosis (and meiosis), characterized by breakdown of the nuclear envelope and condensing of the chromatin to form chromosomes

proteasomes

Nonmembranous organelle that recycle faulty proteins

proteome

full complement of proteins produced by a cell (determined by the cell’s specific gene expression)

reactive oxygen species (ROS)

a group of extremely reactive peroxides and oxygen-containing radicals that may contribute to cellular damage

receptor

protein molecule that contains a binding site for another specific molecule (called a ligand)

receptor-mediated endocytosis

endocytosis of ligands attached to membrane-bound receptors

ribosomal RNA (rRNA)

RNA that makes up the subunits of a ribosome

ribosome

cellular organelle that functions in protein synthesis

Rough ER (RER)

Endoplasmic reticulum with its membrane dotted with ribosomes

RNA polymerase

enzyme that unwinds DNA and then adds new nucleotides to a growing strand of RNA for the transcription phase of protein synthesis

S phase

stage of the cell cycle during which DNA replication occurs

selective permeability

feature of any barrier that allows certain substances to cross but excludes others

sister chromatid

one of a pair of identical chromosomes, formed during DNA replication

sodium-potassium pump

(also, Na+/K+ ATP-ase) membrane-embedded protein pump that uses ATP to move Na+ out of a cell and K+ into the cell

smooth ER (SER)

Endoplasmic reticulum without ribosomes associated with its membrane

spliceosome

complex of enzymes that serves to splice out the introns of a pre-mRNA transcript

splicing

the process of modifying a pre-mRNA transcript by removing certain, typically non-coding, regions

telophase

final stage of mitosis (and meiosis), preceding cytokinesis, characterized by the formation of two new daughter nuclei

transcription

process of producing an mRNA molecule that is complementary to a particular gene of DNA

transfer RNA (tRNA)

molecules of RNA that serve to bring amino acids to a growing polypeptide strand and properly place them into the sequence

translation

process of producing a protein from the nucleotide sequence code of an mRNA transcript

tubulin

protein that polymerizes into long chains or filaments that form microtubules

vesicle

membrane-bound structure that contains materials within or outside of the cell

4. Tissue

adipocytes

lipid storage cells

adipose tissue

specialized areolar tissue dominated by adipocytes

anchoring junction

mechanically attaches adjacent cells to each other or to the basement membrane

apical

that part of a cell or tissue which, in general, faces an open space

apocrine secretion

release of a substance along with the apical portion of the cell

apoptosis

programmed cell death

areolar tissue

(also, loose connective tissue) a type of connective tissue proper that shows little specialization with cells dispersed in the matrix

atrophy

loss of mass and function

basal lamina

thin extracellular layer that lies underneath epithelial cells and separates them from other tissues

basement membrane

in epithelial tissue, a thin layer of fibrous material that anchors the epithelial tissue to the underlying connective tissue; made up of the basal lamina and reticular lamina

cardiac muscle

heart muscle, under involuntary control, composed of striated cells that attach to form fibers, each cell contains a single nucleus, contracts autonomously

cell junction

point of cell-to-cell contact that connects one cell to another in a tissue

chondrocytes

cells of the cartilage

clotting

also called coagulation; complex process by which blood components form a plug to stop bleeding

collagen fiber

flexible fibrous proteins that give connective tissue tensile strength

connective tissue

type of tissue that serves to hold in place, connect, and integrate the body’s organs and systems

connective tissue membrane

connective tissue that encapsulates organs and lines movable joints

connective tissue proper

connective tissue containing a viscous matrix, fibers, and cells.

cutaneous membrane

skin; epithelial tissue made up of a stratified squamous epithelial cells that cover the outside of the body

dense connective tissue

connective tissue proper that contains many fibers that provide both elasticity and protection

ectoderm

outermost embryonic germ layer from which the epidermis and the nervous tissue derive

elastic cartilage

type of cartilage, with elastin as the major protein, characterized by rigid support as well as elasticity

elastic fiber

fibrous protein within connective tissue that contains a high percentage of the protein elastin that allows the fibers to stretch and return to original size

endocrine gland

groups of cells that release chemical signals into the intercellular fluid to be picked up and transported to their target organs by blood

endoderm

innermost embryonic germ layer from which most of the digestive system and lower respiratory system derive

endothelium

tissue that lines vessels of the lymphatic and cardiovascular system, made up of a simple squamous epithelium

epithelial membrane

epithelium attached to a layer of connective tissue

epithelial tissue

type of tissue that serves primarily as a covering or lining of body parts, protecting the body; it also functions in absorption, transport, and secretion

exocrine gland

group of epithelial cells that secrete substances through ducts that open to the skin or to internal body surfaces that lead to the exterior of the body

fibroblast

most abundant cell type in connective tissue, secretes protein fibers and matrix into the extracellular space

fibrocartilage

tough form of cartilage, made of thick bundles of collagen fibers embedded in chondroitin sulfate ground substance

fibrocyte

less active form of fibroblast

fluid connective tissue

specialized cells that circulate in a watery fluid containing salts, nutrients, and dissolved proteins

gap junction

allows cytoplasmic communications to occur between cells

goblet cell

unicellular gland found in columnar epithelium that secretes mucous

ground substance

fluid or semi-fluid portion of the matrix

histamine

chemical compound released by mast cells in response to injury that causes vasodilation and endothelium permeability

histology

microscopic study of tissue architecture, organization, and function

holocrine secretion

release of a substance caused by the rupture of a gland cell, which becomes part of the secretion

hyaline cartilage

most common type of cartilage, smooth and made of short collagen fibers embedded in a chondroitin sulfate ground substance

inflammation

response of tissue to injury

lacunae

(singular = lacuna) small spaces in bone or cartilage tissue that cells occupy

lamina propria

areolar connective tissue underlying a mucous membrane

loose connective tissue

(also, areolar tissue) type of connective tissue proper that shows little specialization with cells dispersed in the matrix

matrix

extracellular material which is produced by the cells embedded in it, containing ground substance and fibers

merocrine secretion

release of a substance from a gland via exocytosis

mesenchymal cell

adult stem cell from which most connective tissue cells are derived

mesenchyme

embryonic tissue from which connective tissue cells derive

mesoderm

middle embryonic germ layer from which connective tissue, muscle tissue, and some epithelial tissue derive

mesothelium

simple squamous epithelial tissue which covers the major body cavities and is the epithelial portion of serous membranes

mucous connective tissue

specialized loose connective tissue present in the umbilical cord

mucous gland

group of cells that secrete mucous, a thick, slippery substance that keeps tissues moist and acts as a lubricant

mucous membrane

tissue membrane that is covered by protective mucous and lines tissue exposed to the outside environment

muscle tissue

type of tissue that is capable of contracting and generating tension in response to stimulation; produces movement.

myelin

layer of lipid inside some neuroglial cells that wraps around the axons of some neurons

myocyte

muscle cells

necrosis

accidental death of cells and tissues

nervous tissue

type of tissue that is capable of sending and receiving impulses through electrochemical signals.

neuroglia

supportive neural cells

neuron

excitable neural cell that transfer nerve impulses

parenchyma

functional cells of a gland or organ, in contrast with the supportive or connective tissue of a gland or organ

pseudostratified columnar epithelium

tissue that consists of a single layer of irregularly shaped and sized cells that give the appearance of multiple layers; found in ducts of certain glands and the upper respiratory tract

reticular fiber

fine fibrous protein, made of collagen subunits, which cross-link to form supporting “nets” within connective tissue

reticular lamina

matrix containing collagen and elastin secreted by connective tissue; a component of the basement membrane

reticular tissue

type of loose connective tissue that provides a supportive framework to soft organs, such as lymphatic tissue, spleen, and the liver

serous gland

group of cells within the serous membrane that secrete a lubricating substance onto the surface

serous membrane

type of tissue membrane that lines body cavities and lubricates them with serous fluid

simple columnar epithelium

tissue that consists of a single layer of column-like cells; promotes secretion and absorption in tissues and organs

simple cuboidal epithelium

tissue that consists of a single layer of cube-shaped cells; promotes secretion and absorption in ducts and tubules

simple squamous epithelium

tissue that consists of a single layer of flat scale-like cells; promotes diffusion and filtration across surface

skeletal muscle

usually attached to bone, under voluntary control, each cell is a fiber that is multinucleated and striated

smooth muscle

under involuntary control, moves internal organs, cells contain a single nucleus, are spindle-shaped, and do not appear striated; each cell is a fiber

stratified columnar epithelium

tissue that consists of two or more layers of column-like cells, contains glands and is found in some ducts

stratified cuboidal epithelium

tissue that consists of two or more layers of cube-shaped cells, found in some ducts

stratified squamous epithelium

tissue that consists of multiple layers of cells with the most apical being flat scale-like cells; protects surfaces from abrasion

striation

alignment of parallel actin and myosin filaments which form a banded pattern

supportive connective tissue

type of connective tissue that provides strength to the body and protects soft tissue

synovial membrane

connective tissue membrane that lines the cavities of freely movable joints, producing synovial fluid for lubrication

tight junction

forms an impermeable barrier between cells

tissue

group of cells that are similar in form and perform related functions

tissue membrane

thin layer or sheet of cells that covers the outside of the body, organs, and internal cavities

totipotent

embryonic cells that have the ability to differentiate into any type of cell and organ in the body

transitional epithelium

form of stratified epithelium found in the urinary tract, characterized by an apical layer of cells that change shape in response to the presence of urine

vasodilation

widening of blood vessels

wound contraction

process whereby the borders of a wound are physically drawn together

5. Skin

acne

skin condition due to infected sebaceous glands

albinism

genetic disorder that affects the skin, in which there is no melanin production

anagen

active phase of the hair growth cycle

apocrine sweat gland

type of sweat gland that is associated with hair follicles in the armpits and genital regions

arrector pili

smooth muscle that is activated in response to external stimuli that pull on hair follicles and make the hair “stand up”

basal cell

type of stem cell found in the stratum basale and in the hair matrix that continually undergoes cell division, producing the keratinocytes of the epidermis

basal cell carcinoma

cancer that originates from basal cells in the epidermis of the skin

bedsore

sore on the skin that develops when regions of the body start necrotizing due to constant pressure and lack of blood supply; also called decubitis ulcers

callus

thickened area of skin that arises due to constant abrasion

catagen

transitional phase marking the end of the anagen phase of the hair growth cycle

corn

type of callus that is named for its shape and the elliptical motion of the abrasive force

cortex

in hair, the second or middle layer of keratinocytes originating from the hair matrix, as seen in a cross-section of the hair bulb

cuticle

in hair, the outermost layer of keratinocytes originating from the hair matrix, as seen in a cross-section of the hair bulb

dermal papilla

(plural = dermal papillae) extension of the papillary layer of the dermis that increases surface contact between the epidermis and dermis

dermis

layer of skin between the epidermis and hypodermis, composed mainly of connective tissue and containing blood vessels, hair follicles, sweat glands, and other structures

desmosome

structure that forms an impermeable junction between cells

eccrine sweat gland

type of sweat gland that is common throughout the skin surface; it produces a hypotonic sweat for thermoregulation

eczema

skin condition due to an allergic reaction, which resembles a rash

elastin fibers

fibers made of the protein elastin that increase the elasticity of the dermis

eleiden

clear protein-bound lipid found in the stratum lucidum that is derived from keratohyalin and helps to prevent water loss

epidermis

outermost tissue layer of the skin

eponychium

nail fold that meets the proximal end of the nail body, also called the cuticle

external root sheath

outer layer of the hair follicle that is an extension of the epidermis, which encloses the hair root

first-degree burn

superficial burn that injures only the epidermis

fourth-degree burn

burn in which full thickness of the skin and underlying muscle and bone is damaged

glassy membrane

layer of connective tissue that surrounds the base of the hair follicle, connecting it to the dermis

hair

keratinous filament growing out of the epidermis

hair bulb

structure at the base of the hair root that surrounds the dermal papilla

hair follicle

cavity or sac from which hair originates

hair matrix

layer of basal cells from which a strand of hair grows

hair papilla

mass of connective tissue, blood capillaries, and nerve endings at the base of the hair follicle

hair root

part of hair that is below the epidermis anchored to the follicle

hair shaft

part of hair that is above the epidermis but is not anchored to the follicle

hypodermis

connective tissue connecting the integument to the underlying bone and muscle

hyponychium

thickened layer of stratum corneum that lies below the free edge of the nail

integumentary system

skin and its accessory structures

internal root sheath

innermost layer of keratinocytes in the hair follicle that surround the hair root up to the hair shaft

keloid

type of scar that has layers raised above the skin surface

keratin

type of structural protein that gives skin, hair, and nails its hard, water-resistant properties

keratinocyte

cell that produces keratin and is the most predominant type of cell found in the epidermis

keratohyalin

granulated protein found in the stratum granulosum

Langerhans cell

specialized dendritic cell found in the stratum spinosum that functions as a macrophage

lunula

basal part of the nail body that consists of a crescent-shaped layer of thick epithelium

medulla

in hair, the innermost layer of keratinocytes originating from the hair matrix

Meissner corpuscle

(also, tactile corpuscle) receptor in the skin that responds to light touch

melanin

pigment that determines the color of hair and skin

melanocyte

cell found in the stratum basale of the epidermis that produces the pigment melanin

melanoma

type of skin cancer that originates from the melanocytes of the skin

melanosome

intercellular vesicle that transfers melanin from melanocytes into keratinocytes of the epidermis

Merkel cell

receptor cell in the stratum basale of the epidermis that responds to the sense of touch

metastasis

spread of cancer cells from a source to other parts of the body

nail bed

layer of epidermis upon which the nail body forms

nail body

main keratinous plate that forms the nail

nail cuticle

fold of epithelium that extends over the nail bed, also called the eponychium

nail fold

fold of epithelium at that extend over the sides of the nail body, holding it in place

nail root

part of the nail that is lodged deep in the epidermis from which the nail grows

Pacinian corpuscle

(also, lamellated corpuscle) receptor in the skin that responds to vibration

papillary layer

superficial layer of the dermis, made of loose, areolar connective tissue

reticular layer

deeper layer of the dermis; it has a reticulated appearance due to the presence of abundant collagen and elastin fibers

rickets

disease in children caused by vitamin D deficiency, which leads to the weakening of bones

scar

collagen-rich skin formed after the process of wound healing that is different from normal skin

sebaceous gland

type of oil gland found in the dermis all over the body and helps to lubricate and waterproof the skin and hair by secreting sebum

sebum

oily substance that is composed of a mixture of lipids that lubricates the skin and hair

second-degree burn

partial-thickness burn that injures the epidermis and a portion of the dermis

squamous cell carcinoma

type of skin cancer that originates from the stratum spinosum of the epidermis

stratum basale

deepest layer of the epidermis, made of epidermal stem cells

stratum corneum

most superficial layer of the epidermis

stratum granulosum

layer of the epidermis superficial to the stratum spinosum

stratum lucidum

layer of the epidermis between the stratum granulosum and stratum corneum, found only in thick skin covering the palms, soles of the feet, and digits

stratum spinosum

layer of the epidermis superficial to the stratum basale, characterized by the presence of desmosomes

stretch mark

mark formed on the skin due to a sudden growth spurt and expansion of the dermis beyond its elastic limits

sudoriferous gland

sweat gland

telogen

resting phase of the hair growth cycle initiated with catagen and terminated by the beginning of a new anagen phase of hair growth

third-degree burn

burn that penetrates and destroys the full thickness of the skin (epidermis and dermis)

vitamin D

compound that aids absorption of calcium and phosphates in the intestine to improve bone health

vitiligo

skin condition in which melanocytes in certain areas lose the ability to produce melanin, possibly due an autoimmune reaction that leads to loss of color in patches

6. Osseous tissue

articular cartilage

thin layer of cartilage covering an epiphysis; reduces friction and acts as a shock absorber

articulation

where two bone surfaces meet

bone

hard, dense connective tissue that forms the structural elements of the skeleton

canaliculi

(singular = canaliculus) channels within the bone matrix that house one of an osteocyte’s many cytoplasmic extensions that it uses to communicate and receive nutrients

cartilage

semi-rigid connective tissue found on the skeleton in areas where flexibility and smooth surfaces support movement

central canal

longitudinal channel in the center of each osteon; contains blood vessels, nerves, and lymphatic vessels; also known as the Haversian canal

closed reduction

manual manipulation of a broken bone to set it into its natural position without surgery

compact bone

dense osseous tissue that can withstand compressive forces

diaphysis

tubular shaft that runs between the proximal and distal ends of a long bone

diploë

layer of spongy bone, that is sandwiched between two the layers of compact bone found in flat bones

endochondral ossification

process in which bone forms by replacing hyaline cartilage

endosteum

delicate membranous lining of a bone’s medullary cavity

epiphyseal line

completely ossified remnant of the epiphyseal plate

epiphyseal plate

(also, growth plate) sheet of hyaline cartilage in the metaphysis of an immature bone; replaced by bone tissue as the organ grows in length

epiphysis

wide section at each end of a long bone; filled with spongy bone and red marrow

external callus

collar of hyaline cartilage and bone that forms around the outside of a fracture

flat bone

thin and curved bone; serves as a point of attachment for muscles and protects internal organs

fracture

broken bone

fracture hematoma

blood clot that forms at the site of a broken bone

hematopoiesis

production of blood cells, which occurs in the red marrow of the bones

hole

opening or depression in a bone

hypercalcemia

condition characterized by abnormally high levels of calcium

hypocalcemia

condition characterized by abnormally low levels of calcium

internal callus

fibrocartilaginous matrix, in the endosteal region, between the two ends of a broken bone

intramembranous ossification

process by which bone forms directly from mesenchymal tissue

irregular bone

bone of complex shape; protects internal organs from compressive forces

lacunae

(singular = lacuna) spaces in a bone that house an osteocyte

long bone

cylinder-shaped bone that is longer than it is wide; functions as a lever

medullary cavity

hollow region of the diaphysis; filled with yellow marrow

modeling

process, during bone growth, by which bone is resorbed on one surface of a bone and deposited on another

nutrient foramen

small opening in the middle of the external surface of the diaphysis, through which an artery enters the bone to provide nourishment

open reduction

surgical exposure of a bone to reset a fracture

orthopedist

doctor who specializes in diagnosing and treating musculoskeletal disorders and injuries

osseous tissue

bone tissue; a hard, dense connective tissue that forms the structural elements of the skeleton

ossification

(also, osteogenesis) bone formation

ossification center

cluster of osteoblasts found in the early stages of intramembranous ossification

osteoblast

cell responsible for forming new bone

osteoclast

cell responsible for resorbing bone

osteocyte

primary cell in mature bone; responsible for maintaining the matrix

osteogenic cell

undifferentiated cell with high mitotic activity; the only bone cells that divide; they differentiate and develop into osteoblasts

osteoid

uncalcified bone matrix secreted by osteoblasts

osteon

(also, Haversian system) basic structural unit of compact bone; made of concentric layers of calcified matrix

osteoporosis

disease characterized by a decrease in bone mass; occurs when the rate of bone resorption exceeds the rate of bone formation, a common occurrence as the body ages

perforating canal

(also, Volkmann’s canal) channel that branches off from the central canal and houses vessels and nerves that extend to the periosteum and endosteum

perichondrium

membrane that covers cartilage

periosteum

fibrous membrane covering the outer surface of bone and continuous with ligaments

primary ossification center

region, deep in the periosteal collar, where bone development starts during endochondral ossification

projection

bone markings where part of the surface sticks out above the rest of the surface, where tendons and ligaments attach

proliferative zone

region of the epiphyseal plate that makes new chondrocytes to replace those that die at the diaphyseal end of the plate and contributes to longitudinal growth of the epiphyseal plate

red marrow

connective tissue in the interior cavity of a bone where hematopoiesis takes place

remodeling

process by which osteoclasts resorb old or damaged bone at the same time as and on the same surface where osteoblasts form new bone to replace that which is resorbed

reserve zone

region of the epiphyseal plate that anchors the plate to the osseous tissue of the epiphysis

secondary ossification center

region of bone development in the epiphyses

sesamoid bone

small, round bone embedded in a tendon; protects the tendon from compressive forces

short bone

cube-shaped bone that is approximately equal in length, width, and thickness; provides limited motion

skeletal system

organ system composed of bones and cartilage that provides for movement, support, and protection

spongy bone

(also, cancellous bone) trabeculated osseous tissue that supports shifts in weight distribution

trabeculae

(singular = trabecula) spikes or sections of the lattice-like matrix in spongy bone

yellow marrow

connective tissue in the interior cavity of a bone where fat is stored

zone of calcified matrix

region of the epiphyseal plate closest to the diaphyseal end; functions to connect the epiphyseal plate to the diaphysis

zone of maturation and hypertrophy

region of the epiphyseal plate where chondrocytes from the proliferative zone grow and mature and contribute to the longitudinal growth of the epiphyseal plate

7. Axial Skeleton

alveolar process of the mandible

upper border of mandibular body that contains the lower teeth

alveolar process of the maxilla

curved, inferior margin of the maxilla that supports and anchors the upper teeth

angle of the mandible

rounded corner located at outside margin of the body and ramus junction

angle of the rib

portion of rib with greatest curvature; together, the rib angles form the most posterior extent of the thoracic cage

anterior (ventral) sacral foramen

one of the series of paired openings located on the anterior (ventral) side of the sacrum

anterior arch

anterior portion of the ring-like C1 (atlas) vertebra

anterior cranial fossa

shallowest and most anterior cranial fossa of the cranial base that extends from the frontal bone to the lesser wing of the sphenoid bone

anterior longitudinal ligament

ligament that runs the length of the vertebral column, uniting the anterior aspects of the vertebral bodies

anulus fibrosus

tough, fibrous outer portion of an intervertebral disc, which is strongly anchored to the bodies of the adjacent vertebrae

appendicular skeleton

all bones of the upper and lower limbs, plus the girdle bones that attach each limb to the axial skeleton

articular tubercle

smooth ridge located on the inferior skull, immediately anterior to the mandibular fossa

atlas

first cervical (C1) vertebra

axial skeleton

central, vertical axis of the body, including the skull, vertebral column, and thoracic cage

axis

second cervical (C2) vertebra

body of the rib

shaft portion of a rib

brain case

portion of the skull that contains and protects the brain, consisting of the eight bones that form the cranial base and rounded upper skull

calvaria

(also, skullcap) rounded top of the skull

carotid canal

zig-zag tunnel providing passage through the base of the skull for the internal carotid artery to the brain; begins anteromedial to the styloid process and terminates in the middle cranial cavity, near the posterior-lateral base of the sella turcica

cervical curve

posteriorly concave curvature of the cervical vertebral column region; a secondary curve of the vertebral column

cervical vertebrae

seven vertebrae numbered as C1–C7 that are located in the neck region of the vertebral column

clavicular notch

paired notches located on the superior-lateral sides of the sternal manubrium, for articulation with the clavicle

coccyx

small bone located at inferior end of the adult vertebral column that is formed by the fusion of four coccygeal vertebrae; also referred to as the “tailbone”

condylar process of the mandible

thickened upward projection from posterior margin of mandibular ramus

condyle

oval-shaped process located at the top of the condylar process of the mandible

coronal suture

joint that unites the frontal bone to the right and left parietal bones across the top of the skull

coronoid process of the mandible

flattened upward projection from the anterior margin of the mandibular ramus

costal cartilage

hyaline cartilage structure attached to the anterior end of each rib that provides for either direct or indirect attachment of most ribs to the sternum

costal facet

site on the lateral sides of a thoracic vertebra for articulation with the head of a rib

costal groove

shallow groove along the inferior margin of a rib that provides passage for blood vessels and a nerve

cranial cavity

interior space of the skull that houses the brain

cranium

skull

cribriform plate

small, flattened areas with numerous small openings, located to either side of the midline in the floor of the anterior cranial fossa; formed by the ethmoid bone

crista galli

small upward projection located at the midline in the floor of the anterior cranial fossa; formed by the ethmoid bone

dens

bony projection (odontoid process) that extends upward from the body of the C2 (axis) vertebra

ear ossicles

three small bones located in the middle ear cavity that serve to transmit sound vibrations to the inner ear

ethmoid air cell

one of several small, air-filled spaces located within the lateral sides of the ethmoid bone, between the orbit and upper nasal cavity

ethmoid bone

unpaired bone that forms the roof and upper, lateral walls of the nasal cavity, portions of the floor of the anterior cranial fossa and medial wall of orbit, and the upper portion of the nasal septum

external acoustic meatus

ear canal opening located on the lateral side of the skull

external occipital protuberance

small bump located at the midline on the posterior skull

facet

small, flattened area on a bone for an articulation (joint) with another bone, or for muscle attachment

facial bones

fourteen bones that support the facial structures and form the upper and lower jaws and the hard palate

false ribs

vertebrochondral ribs 8–12 whose costal cartilage either attaches indirectly to the sternum via the costal cartilage of the next higher rib or does not attach to the sternum at all

floating ribs

vertebral ribs 11–12 that do not attach to the sternum or to the costal cartilage of another rib

fontanelle

expanded area of fibrous connective tissue that separates the brain case bones of the skull prior to birth and during the first year after birth

foramen lacerum

irregular opening in the base of the skull, located inferior to the exit of carotid canal

foramen magnum

large opening in the occipital bone of the skull through which the spinal cord emerges and the vertebral arteries enter the cranium

foramen ovale of the middle cranial fossa

oval-shaped opening in the floor of the middle cranial fossa

foramen rotundum

round opening in the floor of the middle cranial fossa, located between the superior orbital fissure and foramen ovale

foramen spinosum

small opening in the floor of the middle cranial fossa, located lateral to the foramen ovale

frontal bone

unpaired bone that forms forehead, roof of orbit, and floor of anterior cranial fossa

frontal sinus

air-filled space within the frontal bone; most anterior of the paranasal sinuses

glabella

slight depression of frontal bone, located at the midline between the eyebrows

greater wings of sphenoid bone

lateral projections of the sphenoid bone that form the anterior wall of the middle cranial fossa and an area of the lateral skull

hard palate

bony structure that forms the roof of the mouth and floor of the nasal cavity, formed by the palatine process of the maxillary bones and the horizontal plate of the palatine bones

head of the rib

posterior end of a rib that articulates with the bodies of thoracic vertebrae

horizontal plate

medial extension from the palatine bone that forms the posterior quarter of the hard palate

hyoid bone

small, U-shaped bone located in upper neck that does not contact any other bone

hypoglossal canal

paired openings that pass anteriorly from the anterior-lateral margins of the foramen magnum deep to the occipital condyles

hypophyseal (pituitary) fossa

shallow depression on top of the sella turcica that houses the pituitary (hypophyseal) gland

inferior articular process

bony process that extends downward from the vertebral arch of a vertebra that articulates with the superior articular process of the next lower vertebra

inferior nasal concha

one of the paired bones that project from the lateral walls of the nasal cavity to form the largest and most inferior of the nasal conchae

infraorbital foramen

opening located on anterior skull, below the orbit

internal acoustic meatus

opening into petrous ridge, located on the lateral wall of the posterior cranial fossa

intervertebral disc

structure located between the bodies of adjacent vertebrae that strongly joins the vertebrae; provides padding, weight bearing ability, and enables vertebral column movements

intervertebral foramen

opening located between adjacent vertebrae for exit of a spinal nerve

jugular (suprasternal) notch

shallow notch located on superior surface of sternal manubrium

jugular foramen

irregularly shaped opening located in the lateral floor of the posterior cranial cavity

kyphosis

(also, humpback or hunchback) excessive posterior curvature of the thoracic vertebral column region

lacrimal bone

paired bones that contribute to the anterior-medial wall of each orbit

lacrimal fossa

shallow depression in the anterior-medial wall of the orbit, formed by the lacrimal bone that gives rise to the nasolacrimal canal

lambdoid suture

inverted V-shaped joint that unites the occipital bone to the right and left parietal bones on the posterior skull

lamina

portion of the vertebral arch on each vertebra that extends between the transverse and spinous process

lateral sacral crest

paired irregular ridges running down the lateral sides of the posterior sacrum that was formed by the fusion of the transverse processes from the five sacral vertebrae

lesser wings of the sphenoid bone

lateral extensions of the sphenoid bone that form the bony lip separating the anterior and middle cranial fossae

ligamentum flavum

series of short ligaments that unite the lamina of adjacent vertebrae

lingula

small flap of bone located on the inner (medial) surface of mandibular ramus, next to the mandibular foramen

lordosis

(also, swayback) excessive anterior curvature of the lumbar vertebral column region

lumbar curve

posteriorly concave curvature of the lumbar vertebral column region; a secondary curve of the vertebral column

lumbar vertebrae

five vertebrae numbered as L1–L5 that are located in lumbar region (lower back) of the vertebral column

mandible

unpaired bone that forms the lower jaw bone; the only moveable bone of the skull

mandibular foramen

opening located on the inner (medial) surface of the mandibular ramus

mandibular fossa

oval depression located on the inferior surface of the skull

mandibular notch

large U-shaped notch located between the condylar process and coronoid process of the mandible

manubrium

expanded, superior portion of the sternum

mastoid process

large bony prominence on the inferior, lateral skull, just behind the earlobe

maxillary bone

(also, maxilla) paired bones that form the upper jaw and anterior portion of the hard palate

maxillary sinus

air-filled space located with each maxillary bone; largest of the paranasal sinuses

median sacral crest

irregular ridge running down the midline of the posterior sacrum that was formed from the fusion of the spinous processes of the five sacral vertebrae

mental foramen

opening located on the anterior-lateral side of the mandibular body

mental protuberance

inferior margin of anterior mandible that forms the chin

middle cranial fossa

centrally located cranial fossa that extends from the lesser wings of the sphenoid bone to the petrous ridge

middle nasal concha

nasal concha formed by the ethmoid bone that is located between the superior and inferior conchae

mylohyoid line

bony ridge located along the inner (medial) surface of the mandibular body

nasal bone

paired bones that form the base of the nose

nasal cavity

opening through skull for passage of air

nasal conchae

curved bony plates that project from the lateral walls of the nasal cavity; include the superior and middle nasal conchae, which are parts of the ethmoid bone, and the independent inferior nasal conchae bone

nasal septum

flat, midline structure that divides the nasal cavity into halves, formed by the perpendicular plate of the ethmoid bone, vomer bone, and septal cartilage

nasolacrimal canal

passage for drainage of tears that extends downward from the medial-anterior orbit to the nasal cavity, terminating behind the inferior nasal conchae

neck of the rib

narrowed region of a rib, next to the rib head

notochord

rod-like structure along dorsal side of the early embryo; largely disappears during later development but does contribute to formation of the intervertebral discs

nuchal ligament

expanded portion of the supraspinous ligament within the posterior neck; interconnects the spinous processes of the cervical vertebrae and attaches to the base of the skull

nucleus pulposus

gel-like central region of an intervertebral disc; provides for padding, weight-bearing, and movement between adjacent vertebrae

occipital bone

unpaired bone that forms the posterior portions of the brain case and base of the skull

occipital condyle

paired, oval-shaped bony knobs located on the inferior skull, to either side of the foramen magnum

optic canal

opening spanning between middle cranial fossa and posterior orbit

orbit

bony socket that contains the eyeball and associated muscles

palatine bone

paired bones that form the posterior quarter of the hard palate and a small area in floor of the orbit

palatine process

medial projection from the maxilla bone that forms the anterior three quarters of the hard palate

paranasal sinuses

cavities within the skull that are connected to the conchae that serve to warm and humidify incoming air, produce mucus, and lighten the weight of the skull; consist of frontal, maxillary, sphenoidal, and ethmoidal sinuses

parietal bone

paired bones that form the upper, lateral sides of the skull

pedicle

portion of the vertebral arch that extends from the vertebral body to the transverse process

perpendicular plate of the ethmoid bone

downward, midline extension of the ethmoid bone that forms the superior portion of the nasal septum

petrous ridge

petrous portion of the temporal bone that forms a large, triangular ridge in the floor of the cranial cavity, separating the middle and posterior cranial fossae; houses the middle and inner ear structures

posterior (dorsal) sacral foramen

one of the series of paired openings located on the posterior (dorsal) side of the sacrum

posterior arch

posterior portion of the ring-like C1 (atlas) vertebra

posterior cranial fossa

deepest and most posterior cranial fossa; extends from the petrous ridge to the occipital bone

posterior longitudinal ligament

ligament that runs the length of the vertebral column, uniting the posterior sides of the vertebral bodies

primary curve

anteriorly concave curvatures of the thoracic and sacrococcygeal regions that are retained from the original fetal curvature of the vertebral column

pterion

H-shaped suture junction region that unites the frontal, parietal, temporal, and sphenoid bones on the lateral side of the skull

ramus of the mandible

vertical portion of the mandible

ribs

thin, curved bones of the chest wall

sacral canal

bony tunnel that runs through the sacrum

sacral foramina

series of paired openings for nerve exit located on both the anterior (ventral) and posterior (dorsal) aspects of the sacrum

sacral hiatus

inferior opening and termination of the sacral canal

sacral promontory

anterior lip of the base (superior end) of the sacrum

sacrococcygeal curve

anteriorly concave curvature formed by the sacrum and coccyx; a primary curve of the vertebral column

sacrum

single bone located near the inferior end of the adult vertebral column that is formed by the fusion of five sacral vertebrae; forms the posterior portion of the pelvis

sagittal suture

joint that unites the right and left parietal bones at the midline along the top of the skull

sclerotome

medial portion of a somite consisting of mesenchyme tissue that will give rise to bone, cartilage, and fibrous connective tissues

scoliosis

abnormal lateral curvature of the vertebral column

secondary curve

posteriorly concave curvatures of the cervical and lumbar regions of the vertebral column that develop after the time of birth

sella turcica

elevated area of sphenoid bone located at midline of the middle cranial fossa

septal cartilage

flat cartilage structure that forms the anterior portion of the nasal septum

skeleton

bones of the body

skull

bony structure that forms the head, face, and jaws, and protects the brain; consists of 22 bones

somite

one of the paired, repeating blocks of tissue located on either side of the notochord in the early embryo

sphenoid bone

unpaired bone that forms the central base of skull

sphenoid sinus

air-filled space located within the sphenoid bone; most posterior of the paranasal sinuses

spinous process

unpaired bony process that extends posteriorly from the vertebral arch of a vertebra

squamous suture

joint that unites the parietal bone to the squamous portion of the temporal bone on the lateral side of the skull

sternal angle

junction line between manubrium and body of the sternum and the site for attachment of the second rib to the sternum

sternum

flattened bone located at the center of the anterior chest

styloid process

downward projecting, elongated bony process located on the inferior aspect of the skull

stylomastoid foramen

opening located on inferior skull, between the styloid process and mastoid process

superior articular process

bony process that extends upward from the vertebral arch of a vertebra that articulates with the inferior articular process of the next higher vertebra

superior articular process of the sacrum

paired processes that extend upward from the sacrum to articulate (join) with the inferior articular processes from the L5 vertebra

superior nasal concha

smallest and most superiorly located of the nasal conchae; formed by the ethmoid bone

superior nuchal line

paired bony lines on the posterior skull that extend laterally from the external occipital protuberance

superior orbital fissure

irregularly shaped opening between the middle cranial fossa and the posterior orbit

supraorbital foramen

opening located on anterior skull, at the superior margin of the orbit

supraorbital margin

superior margin of the orbit

supraspinous ligament

ligament that interconnects the spinous processes of the thoracic and lumbar vertebrae

suture

junction line at which adjacent bones of the skull are united by fibrous connective tissue

temporal bone

paired bones that form the lateral, inferior portions of the skull, with squamous, mastoid, and petrous portions

temporal fossa

shallow space on the lateral side of the skull, above the level of the zygomatic arch

temporal process of the zygomatic bone

short extension from the zygomatic bone that forms the anterior portion of the zygomatic arch

thoracic cage

consists of 12 pairs of ribs and sternum

thoracic curve

anteriorly concave curvature of the thoracic vertebral column region; a primary curve of the vertebral column

thoracic vertebrae

twelve vertebrae numbered as T1–T12 that are located in the thoracic region (upper back) of the vertebral column

transverse foramen

opening found only in the transverse processes of cervical vertebrae

transverse process

paired bony processes that extends laterally from the vertebral arch of a vertebra

true ribs

vertebrosternal ribs 1–7 that attach via their costal cartilage directly to the sternum

tubercle of the rib

small bump on the posterior side of a rib for articulation with the transverse process of a thoracic vertebra

vertebra

individual bone in the neck and back regions of the vertebral column

vertebral (spinal) canal

bony passageway within the vertebral column for the spinal cord that is formed by the series of individual vertebral foramina

vertebral arch

bony arch formed by the posterior portion of each vertebra that surrounds and protects the spinal cord

vertebral column

entire sequence of bones that extend from the skull to the tailbone

vertebral foramen

opening associated with each vertebra defined by the vertebral arch that provides passage for the spinal cord

vomer bone

unpaired bone that forms the inferior and posterior portions of the nasal septum

xiphoid process

small process that forms the inferior tip of the sternum

zygomatic arch

elongated, free-standing arch on the lateral skull, formed anteriorly by the temporal process of the zygomatic bone and posteriorly by the zygomatic process of the temporal bone

zygomatic bone

cheekbone; paired bones that contribute to the lateral orbit and anterior zygomatic arch

zygomatic process of the temporal bone

extension from the temporal bone that forms the posterior portion of the zygomatic arch

8. Appendicular Skeleton

acetabulum

large, cup-shaped cavity located on the lateral side of the hip bone; formed by the junction of the ilium, pubis, and ischium portions of the hip bone

acromial end of the clavicle

lateral end of the clavicle that articulates with the acromion of the scapula

acromial process

acromion of the scapula

acromioclavicular joint

articulation between the acromion of the scapula and the acromial end of the clavicle

acromion

flattened bony process that extends laterally from the scapular spine to form the bony tip of the shoulder

adductor tubercle

small, bony bump located on the superior aspect of the medial epicondyle of the femur

anatomical neck

line on the humerus located around the outside margin of the humeral head

ankle joint

joint that separates the leg and foot portions of the lower limb; formed by the articulations between the talus bone of the foot inferiorly, and the distal end of the tibia, medial malleolus of the tibia, and lateral malleolus of the fibula superiorly

anterior border of the tibia

narrow, anterior margin of the tibia that extends inferiorly from the tibial tuberosity

anterior inferior iliac spine

small, bony projection located on the anterior margin of the ilium, below the anterior superior iliac spine

anterior superior iliac spine

rounded, anterior end of the iliac crest

arcuate line of the ilium

smooth ridge located at the inferior margin of the iliac fossa; forms the lateral portion of the pelvic brim

arm

region of the upper limb located between the shoulder and elbow joints; contains the humerus bone

auricular surface of the ilium

roughened area located on the posterior, medial side of the ilium of the hip bone; articulates with the auricular surface of the sacrum to form the sacroiliac joint

base of the metatarsal bone

expanded, proximal end of each metatarsal bone

bicipital groove

intertubercular groove; narrow groove located between the greater and lesser tubercles of the humerus

calcaneus

heel bone; posterior, inferior tarsal bone that forms the heel of the foot

capitate

from the lateral side, the third of the four distal carpal bones; articulates with the scaphoid and lunate proximally, the trapezoid laterally, the hamate medially, and primarily with the third metacarpal distally

capitulum

knob-like bony structure located anteriorly on the lateral, distal end of the humerus

carpal bone

one of the eight small bones that form the wrist and base of the hand; these are grouped as a proximal row consisting of (from lateral to medial) the scaphoid, lunate, triquetrum, and pisiform bones, and a distal row containing (from lateral to medial) the trapezium, trapezoid, capitate, and hamate bones

carpal tunnel

passageway between the anterior forearm and hand formed by the carpal bones and flexor retinaculum

carpometacarpal joint

articulation between one of the carpal bones in the distal row and a metacarpal bone of the hand

clavicle

collarbone; elongated bone that articulates with the manubrium of the sternum medially and the acromion of the scapula laterally

coracoclavicular ligament

strong band of connective tissue that anchors the coracoid process of the scapula to the lateral clavicle; provides important indirect support for the acromioclavicular joint

coracoid process

short, hook-like process that projects anteriorly and laterally from the superior margin of the scapula

coronoid fossa

depression on the anterior surface of the humerus above the trochlea; this space receives the coronoid process of the ulna when the elbow is maximally flexed

coronoid process of the ulna

projecting bony lip located on the anterior, proximal ulna; forms the inferior margin of the trochlear notch

costoclavicular ligament

band of connective tissue that unites the medial clavicle with the first rib

coxal bone

hip bone

cuboid

tarsal bone that articulates posteriorly with the calcaneus bone, medially with the lateral cuneiform bone, and anteriorly with the fourth and fifth metatarsal bones

deltoid tuberosity

roughened, V-shaped region located laterally on the mid-shaft of the humerus

distal radioulnar joint

articulation between the head of the ulna and the ulnar notch of the radius

distal tibiofibular joint

articulation between the distal fibula and the fibular notch of the tibia

elbow joint

joint located between the upper arm and forearm regions of the upper limb; formed by the articulations between the trochlea of the humerus and the trochlear notch of the ulna, and the capitulum of the humerus and the head of the radius

femur

thigh bone; the single bone of the thigh

fibula

thin, non-weight-bearing bone found on the lateral side of the leg

fibular notch

wide groove on the lateral side of the distal tibia for articulation with the fibula at the distal tibiofibular joint

flexor retinaculum

strong band of connective tissue at the anterior wrist that spans the top of the U-shaped grouping of the carpal bones to form the roof of the carpal tunnel

foot

portion of the lower limb located distal to the ankle joint

forearm

region of the upper limb located between the elbow and wrist joints; contains the radius and ulna bones

fossa

(plural = fossae) shallow depression on the surface of a bone

fovea capitis

minor indentation on the head of the femur that serves as the site of attachment for the ligament to the head of the femur

glenohumeral joint

shoulder joint; formed by the articulation between the glenoid cavity of the scapula and the head of the humerus

glenoid cavity

(also, glenoid fossa) shallow depression located on the lateral scapula, between the superior and lateral borders

gluteal tuberosity

roughened area on the posterior side of the proximal femur, extending inferiorly from the base of the greater trochanter

greater pelvis

(also, greater pelvic cavity or false pelvis) broad space above the pelvic brim defined laterally by the fan-like portion of the upper ilium

greater sciatic foramen

pelvic opening formed by the greater sciatic notch of the hip bone, the sacrum, and the sacrospinous ligament

greater sciatic notch

large, U-shaped indentation located on the posterior margin of the ilium, superior to the ischial spine

greater trochanter

large, bony expansion of the femur that projects superiorly from the base of the femoral neck

greater tubercle

enlarged prominence located on the lateral side of the proximal humerus

hallux

big toe; digit 1 of the foot

hamate

from the lateral side, the fourth of the four distal carpal bones; articulates with the lunate and triquetrum proximally, the fourth and fifth metacarpals distally, and the capitate laterally

hand

region of the upper limb distal to the wrist joint

head of the femur

rounded, proximal end of the femur that articulates with the acetabulum of the hip bone to form the hip joint

head of the fibula

small, knob-like, proximal end of the fibula; articulates with the inferior aspect of the lateral condyle of the tibia

head of the humerus

smooth, rounded region on the medial side of the proximal humerus; articulates with the glenoid fossa of the scapula to form the glenohumeral (shoulder) joint

head of the metatarsal bone

expanded, distal end of each metatarsal bone

head of the radius

disc-shaped structure that forms the proximal end of the radius; articulates with the capitulum of the humerus as part of the elbow joint, and with the radial notch of the ulna as part of the proximal radioulnar joint

head of the ulna

small, rounded distal end of the ulna; articulates with the ulnar notch of the distal radius, forming the distal radioulnar joint

hip bone

coxal bone; single bone that forms the pelvic girdle; consists of three areas, the ilium, ischium, and pubis

hip joint

joint located at the proximal end of the lower limb; formed by the articulation between the acetabulum of the hip bone and the head of the femur

hook of the hamate bone

bony extension located on the anterior side of the hamate carpal bone

humerus

single bone of the upper arm

iliac crest

curved, superior margin of the ilium

iliac fossa

shallow depression found on the anterior and medial surfaces of the upper ilium

ilium

superior portion of the hip bone

inferior angle of the scapula

inferior corner of the scapula located where the medial and lateral borders meet

inferior pubic ramus

narrow segment of bone that passes inferiorly and laterally from the pubic body; joins with the ischial ramus to form the ischiopubic ramus

infraglenoid tubercle

small bump or roughened area located on the lateral border of the scapula, near the inferior margin of the glenoid cavity

infraspinous fossa

broad depression located on the posterior scapula, inferior to the spine

intercondylar eminence

irregular elevation on the superior end of the tibia, between the articulating surfaces of the medial and lateral condyles

intercondylar fossa

deep depression on the posterior side of the distal femur that separates the medial and lateral condyles

intermediate cuneiform

middle of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, medially with the medial cuneiform bone, laterally with the lateral cuneiform bone, and anteriorly with the second metatarsal bone

interosseous border of the fibula

small ridge running down the medial side of the fibular shaft; for attachment of the interosseous membrane between the fibula and tibia

interosseous border of the radius

narrow ridge located on the medial side of the radial shaft; for attachment of the interosseous membrane between the ulna and radius bones

interosseous border of the tibia

small ridge running down the lateral side of the tibial shaft; for attachment of the interosseous membrane between the tibia and fibula

interosseous border of the ulna

narrow ridge located on the lateral side of the ulnar shaft; for attachment of the interosseous membrane between the ulna and radius

interosseous membrane of the forearm

sheet of dense connective tissue that unites the radius and ulna bones

interosseous membrane of the leg

sheet of dense connective tissue that unites the shafts of the tibia and fibula bones

interphalangeal joint

articulation between adjacent phalanx bones of the hand or foot digits

intertrochanteric crest

short, prominent ridge running between the greater and lesser trochanters on the posterior side of the proximal femur

intertrochanteric line

small ridge running between the greater and lesser trochanters on the anterior side of the proximal femur

intertubercular groove (sulcus)

bicipital groove; narrow groove located between the greater and lesser tubercles of the humerus

ischial ramus

bony extension projecting anteriorly and superiorly from the ischial tuberosity; joins with the inferior pubic ramus to form the ischiopubic ramus

ischial spine

pointed, bony projection from the posterior margin of the ischium that separates the greater sciatic notch and lesser sciatic notch

ischial tuberosity

large, roughened protuberance that forms the posteroinferior portion of the hip bone; weight-bearing region of the pelvis when sitting

ischiopubic ramus

narrow extension of bone that connects the ischial tuberosity to the pubic body; formed by the junction of the ischial ramus and inferior pubic ramus

ischium

posteroinferior portion of the hip bone

knee joint

joint that separates the thigh and leg portions of the lower limb; formed by the articulations between the medial and lateral condyles of the femur, and the medial and lateral condyles of the tibia

lateral border of the scapula

diagonally oriented lateral margin of the scapula

lateral condyle of the femur

smooth, articulating surface that forms the distal and posterior sides of the lateral expansion of the distal femur

lateral condyle of the tibia

lateral, expanded region of the proximal tibia that includes the smooth surface that articulates with the lateral condyle of the femur as part of the knee joint

lateral cuneiform

most lateral of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, medially with the intermediate cuneiform bone, laterally with the cuboid bone, and anteriorly with the third metatarsal bone

lateral epicondyle of the femur

roughened area of the femur located on the lateral side of the lateral condyle

lateral epicondyle of the humerus

small projection located on the lateral side of the distal humerus

lateral malleolus

expanded distal end of the fibula

lateral supracondylar ridge

narrow, bony ridge located along the lateral side of the distal humerus, superior to the lateral epicondyle

leg

portion of the lower limb located between the knee and ankle joints

lesser pelvis

(also, lesser pelvic cavity or true pelvis) narrow space located within the pelvis, defined superiorly by the pelvic brim (pelvic inlet) and inferiorly by the pelvic outlet

lesser sciatic foramen

pelvic opening formed by the lesser sciatic notch of the hip bone, the sacrospinous ligament, and the sacrotuberous ligament

lesser sciatic notch

shallow indentation along the posterior margin of the ischium, inferior to the ischial spine

lesser trochanter

small, bony projection on the medial side of the proximal femur, at the base of the femoral neck

lesser tubercle

small, bony prominence located on anterior side of the proximal humerus

linea aspera

longitudinally running bony ridge located in the middle third of the posterior femur

lunate

from the lateral side, the second of the four proximal carpal bones; articulates with the radius proximally, the capitate and hamate distally, the scaphoid laterally, and the triquetrum medially

medial border of the scapula

elongated, medial margin of the scapula

medial condyle of the femur

smooth, articulating surface that forms the distal and posterior sides of the medial expansion of the distal femur

medial condyle of the tibia

medial, expanded region of the proximal tibia that includes the smooth surface that articulates with the medial condyle of the femur as part of the knee joint

medial cuneiform

most medial of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, laterally with the intermediate cuneiform bone, and anteriorly with the first and second metatarsal bones

medial epicondyle of the femur

roughened area of the distal femur located on the medial side of the medial condyle

medial epicondyle of the humerus

enlarged projection located on the medial side of the distal humerus

medial malleolus

bony expansion located on the medial side of the distal tibia

metacarpal bone

one of the five long bones that form the palm of the hand; numbered 1–5, starting on the lateral (thumb) side of the hand

metacarpophalangeal joint

articulation between the distal end of a metacarpal bone of the hand and a proximal phalanx bone of the thumb or a finger

metatarsal bone

one of the five elongated bones that forms the anterior half of the foot; numbered 1–5, starting on the medial side of the foot

metatarsophalangeal joint

articulation between a metatarsal bone of the foot and the proximal phalanx bone of a toe

midcarpal joint

articulation between the proximal and distal rows of the carpal bones; contributes to movements of the hand at the wrist

navicular

tarsal bone that articulates posteriorly with the talus bone, laterally with the cuboid bone, and anteriorly with the medial, intermediate, and lateral cuneiform bones

neck of the femur

narrowed region located inferior to the head of the femur

neck of the radius

narrowed region immediately distal to the head of the radius

obturator foramen

large opening located in the anterior hip bone, between the pubis and ischium regions

olecranon

expanded posterior and superior portions of the proximal ulna; forms the bony tip of the elbow

olecranon fossa

large depression located on the posterior side of the distal humerus; this space receives the olecranon process of the ulna when the elbow is fully extended

patella

kneecap; the largest sesamoid bone of the body; articulates with the distal femur

patellar surface

smooth groove located on the anterior side of the distal femur, between the medial and lateral condyles; site of articulation for the patella

pectineal line

narrow ridge located on the superior surface of the superior pubic ramus

pectoral girdle

shoulder girdle; the set of bones, consisting of the scapula and clavicle, which attaches each upper limb to the axial skeleton

pelvic brim

pelvic inlet; the dividing line between the greater and lesser pelvic regions; formed by the superior margin of the pubic symphysis, the pectineal lines of each pubis, the arcuate lines of each ilium, and the sacral promontory

pelvic girdle

hip girdle; consists of a single hip bone, which attaches a lower limb to the sacrum of the axial skeleton

pelvic inlet

pelvic brim

pelvic outlet

inferior opening of the lesser pelvis; formed by the inferior margin of the pubic symphysis, right and left ischiopubic rami and sacrotuberous ligaments, and the tip of the coccyx

pelvis

ring of bone consisting of the right and left hip bones, the sacrum, and the coccyx

phalanx bone of the foot

(plural = phalanges) one of the 14 bones that form the toes; these include the proximal and distal phalanges of the big toe, and the proximal, middle, and distal phalanx bones of toes two through five

phalanx bone of the hand

(plural = phalanges) one of the 14 bones that form the thumb and fingers; these include the proximal and distal phalanges of the thumb, and the proximal, middle, and distal phalanx bones of the fingers two through five

pisiform

from the lateral side, the fourth of the four proximal carpal bones; articulates with the anterior surface of the triquetrum

pollex

(also, thumb) digit 1 of the hand

posterior inferior iliac spine

small, bony projection located at the inferior margin of the auricular surface on the posterior ilium

posterior superior iliac spine

rounded, posterior end of the iliac crest

proximal radioulnar joint

articulation formed by the radial notch of the ulna and the head of the radius

proximal tibiofibular joint

articulation between the head of the fibula and the inferior aspect of the lateral condyle of the tibia

pubic arch

bony structure formed by the pubic symphysis, and the bodies and inferior pubic rami of the right and left pubic bones

pubic body

enlarged, medial portion of the pubis region of the hip bone

pubic symphysis

joint formed by the articulation between the pubic bodies of the right and left hip bones

pubic tubercle

small bump located on the superior aspect of the pubic body

pubis

anterior portion of the hip bone

radial fossa

small depression located on the anterior humerus above the capitulum; this space receives the head of the radius when the elbow is maximally flexed

radial notch of the ulna

small, smooth area on the lateral side of the proximal ulna; articulates with the head of the radius as part of the proximal radioulnar joint

radial tuberosity

oval-shaped, roughened protuberance located on the medial side of the proximal radius

radiocarpal joint

wrist joint, located between the forearm and hand regions of the upper limb; articulation formed proximally by the distal end of the radius and the fibrocartilaginous pad that unites the distal radius and ulna bone, and distally by the scaphoid, lunate, and triquetrum carpal bones

radius

bone located on the lateral side of the forearm

sacroiliac joint

joint formed by the articulation between the auricular surfaces of the sacrum and ilium

scaphoid

from the lateral side, the first of the four proximal carpal bones; articulates with the radius proximally, the trapezoid, trapezium, and capitate distally, and the lunate medially

scapula

shoulder blade bone located on the posterior side of the shoulder

shaft of the femur

cylindrically shaped region that forms the central portion of the femur

shaft of the fibula

elongated, slender portion located between the expanded ends of the fibula

shaft of the humerus

narrow, elongated, central region of the humerus

shaft of the radius

narrow, elongated, central region of the radius

shaft of the tibia

triangular-shaped, central portion of the tibia

shaft of the ulna

narrow, elongated, central region of the ulna

soleal line

small, diagonally running ridge located on the posterior side of the proximal tibia

spine of the scapula

prominent ridge passing mediolaterally across the upper portion of the posterior scapular surface

sternal end of the clavicle

medial end of the clavicle that articulates with the manubrium of the sternum

sternoclavicular joint

articulation between the manubrium of the sternum and the sternal end of the clavicle; forms the only bony attachment between the pectoral girdle of the upper limb and the axial skeleton

styloid process of the radius

pointed projection located on the lateral end of the distal radius

styloid process of the ulna

short, bony projection located on the medial end of the distal ulna

subpubic angle

inverted V-shape formed by the convergence of the right and left ischiopubic rami; this angle is greater than 80 degrees in females and less than 70 degrees in males

subscapular fossa

broad depression located on the anterior (deep) surface of the scapula

superior angle of the scapula

corner of the scapula between the superior and medial borders of the scapula

superior border of the scapula

superior margin of the scapula

superior pubic ramus

narrow segment of bone that passes laterally from the pubic body to join the ilium

supraglenoid tubercle

small bump located at the superior margin of the glenoid cavity

suprascapular notch

small notch located along the superior border of the scapula, medial to the coracoid process

supraspinous fossa

narrow depression located on the posterior scapula, superior to the spine

surgical neck

region of the humerus where the expanded, proximal end joins with the narrower shaft

sustentaculum tali

bony ledge extending from the medial side of the calcaneus bone

talus

tarsal bone that articulates superiorly with the tibia and fibula at the ankle joint; also articulates inferiorly with the calcaneus bone and anteriorly with the navicular bone

tarsal bone

one of the seven bones that make up the posterior foot; includes the calcaneus, talus, navicular, cuboid, medial cuneiform, intermediate cuneiform, and lateral cuneiform bones

thigh

portion of the lower limb located between the hip and knee joints

tibia

shin bone; the large, weight-bearing bone located on the medial side of the leg

tibial tuberosity

elevated area on the anterior surface of the proximal tibia

trapezium

from the lateral side, the first of the four distal carpal bones; articulates with the scaphoid proximally, the first and second metacarpals distally, and the trapezoid medially

trapezoid

from the lateral side, the second of the four distal carpal bones; articulates with the scaphoid proximally, the second metacarpal distally, the trapezium laterally, and the capitate medially

triquetrum

from the lateral side, the third of the four proximal carpal bones; articulates with the lunate laterally, the hamate distally, and has a facet for the pisiform

trochlea

pulley-shaped region located medially at the distal end of the humerus; articulates at the elbow with the trochlear notch of the ulna

trochlear notch

large, C-shaped depression located on the anterior side of the proximal ulna; articulates at the elbow with the trochlea of the humerus

ulna

bone located on the medial side of the forearm

ulnar notch of the radius

shallow, smooth area located on the medial side of the distal radius; articulates with the head of the ulna at the distal radioulnar joint

ulnar tuberosity

roughened area located on the anterior, proximal ulna inferior to the coronoid process

9. Joints

amphiarthrosis

slightly mobile joint

anterior cruciate ligament

intracapsular ligament of the knee; extends from anterior, superior surface of the tibia to the inner aspect of the lateral condyle of the femur; resists hyperextension of knee

articular capsule

connective tissue structure that encloses the joint cavity of a synovial joint

articular cartilage

thin layer of hyaline cartilage that covers the articulating surfaces of bones at a synovial joint

articulation

joint of the body

biaxial joint

type of diarthrosis; a joint that allows for movements within two planes (two axes)

bursa

connective tissue sac containing lubricating fluid that prevents friction between adjacent structures, such as skin and bone, tendons and bone, or between muscles

cartilaginous joint

joint at which the bones are united by hyaline cartilage (synchondrosis) or fibrocartilage (symphysis)

diarthrosis

freely mobile joint

elbow joint

humeroulnar joint

extrinsic ligament

ligament located outside of the articular capsule of a synovial joint

fibrous joint

joint where the articulating areas of the adjacent bones are connected by fibrous connective tissue

fibular collateral ligament

extrinsic ligament of the knee joint that spans from the lateral epicondyle of the femur to the head of the fibula; resists hyperextension and rotation of the extended knee

fontanelles

expanded areas of fibrous connective tissue that separate the braincase bones of the skull prior to birth and during the first year after birth

glenohumeral joint

shoulder joint; articulation between the glenoid cavity of the scapula and head of the humerus; multiaxial ball-and-socket joint that allows for flexion/extension, abduction/adduction, circumduction, and medial/lateral rotation of the humerus

glenoid labrum

lip of fibrocartilage located around the outside margin of the glenoid cavity of the scapula

gomphosis

type of fibrous joint in which the root of a tooth is anchored into its bony jaw socket by strong periodontal ligaments

hip joint

multiaxial ball-and-socket joint between the head of the femur and the acetabulum of the hip bone

interosseous membrane

wide sheet of fibrous connective tissue that fills the gap between two parallel bones, forming a syndesmosis; found between the radius and ulna of the forearm and between the tibia and fibula of the leg

intracapsular ligament

ligament that is located within the articular capsule of a synovial joint

intrinsic ligament

ligament that is fused to or incorporated into the wall of the articular capsule of a synovial joint

joint

site at which two or more bones or bone and cartilage come together (articulate)

joint cavity

space enclosed by the articular capsule of a synovial joint that is filled with synovial fluid and contains the articulating surfaces of the adjacent bones

knee joint

consists of three articulations. The medial and lateral tibiofemoral joints are the articulations between the rounded condyles of the femur and the relatively flat condyles of the tibia. In addition, the femoropatellar joint is found between the patella and the distal femur.

lateral meniscus

C-shaped fibrocartilage articular disc located at the knee, between the lateral condyle of the femur and the lateral condyle of the tibia

ligament

strong band of dense connective tissue spanning between bones

medial meniscus

C-shaped fibrocartilage articular disc located at the knee, between the medial condyle of the femur and medial condyle of the tibia

meniscus

articular disc

multiaxial joint

type of diarthrosis; a joint that allows for movements within three planes (three axes)

posterior cruciate ligament

intracapsular ligament of the knee; extends from the posterior, superior surface of the tibia to the inner aspect of the medial condyle of the femur; prevents anterior displacement of the femur when the knee is flexed and weight bearing

rotator cuff

strong connective tissue structure formed by the fusion of four rotator cuff muscle tendons to the articular capsule of the shoulder joint; surrounds and supports superior, anterior, lateral, and posterior sides of the humeral head

suture

fibrous joint that connects the bones of the skull (except the mandible); an immobile joint (synarthrosis)

symphysis

type of cartilaginous joint where the bones are joined by fibrocartilage

synarthrosis

immobile or nearly immobile joint

synchondrosis

type of cartilaginous joint where the bones are joined by hyaline cartilage

syndesmosis

type of fibrous joint in which two separated, parallel bones are connected by an interosseous membrane

synostosis

site at which adjacent bones or bony components have fused together

synovial fluid

thick, lubricating fluid that fills the interior of a synovial joint

synovial joint

joint at which the articulating surfaces of the bones are located within a joint cavity formed by an articular capsule

synovial membrane

thin layer that lines the inner surface of the joint cavity at a synovial joint; produces the synovial fluid

temporomandibular joint (TMJ)

articulation between the condyle of the mandible and the mandibular fossa and articular tubercle of the temporal bone of the skull; allows for depression/elevation (opening/closing of mouth), protraction/retraction, and side-to-side motions of the mandible

tendon

dense connective tissue structure that anchors a muscle to bone

tibial collateral ligament

extrinsic ligament of knee joint that spans from the medial epicondyle of the femur to the medial tibia; resists hyperextension and rotation of extended knee

uniaxial joint

type of diarthrosis; joint that allows for motion within only one plane (one axis)

10. Muscle tissue

acetylcholine (ACh)

neurotransmitter that binds at a motor end-plate to trigger depolarization

actin

protein that makes up most of the thin myofilaments in a sarcomere muscle fiber

aerobic respiration

production of ATP in the presence of oxygen

anaerobic glycolysis

a non-oxygen-dependent process that breaks down glucose (sugar) to produce ATP

angiogenesis

formation of blood capillary networks

aponeurosis

broad, tendon-like sheet of connective tissue that attaches a skeletal muscle to another skeletal muscle or to a bone

atrophy

loss of structural proteins from muscle fibers

cardiac muscle

striated muscle found in the heart; joined to one another at intercalated discs and under the regulation of pacemaker cells, which contract as one unit to pump blood through the circulatory system. Cardiac muscle is under involuntary control.

concentric contraction

muscle contraction that shortens the muscle to move a load

contraction phase

twitch contraction phase when tension increases

creatine phosphate

phosphagen used to store energy from ATP and transfer it to muscle

eccentric contraction

muscle contraction that lengthens the muscle as the tension is diminished

elasticity

ability to stretch and rebound

endomysium

loose, and well-hydrated connective tissue covering each muscle fiber in a skeletal muscle

epimysium

outer layer of connective tissue around a skeletal muscle

excitation-contraction coupling

sequence of events from motor neuron signaling to a skeletal muscle fiber to contraction of the fiber’s sarcomeres

fascicle

bundle of muscle fibers within a skeletal muscle

fast glycolytic (FG)

muscle fiber that primarily uses anaerobic glycolysis

fast oxidative (FO)

intermediate muscle fiber that is between slow oxidative and fast glycolytic fibers

hypertonia

abnormally high muscle tone

hypertrophy

addition of structural proteins to muscle fibers

hypotonia

abnormally low muscle tone caused by the absence of low-level contractions

intercalated disc

part of the sarcolemma that connects cardiac tissue, and contains gap junctions and desmosomes

isometric contraction

muscle contraction that occurs with no change in muscle length

isotonic contraction

muscle contraction that involves changes in muscle length

lactic acid

product of anaerobic glycolysis

latent period

the time when a twitch does not produce contraction

motor end-plate

sarcolemma of muscle fiber at the neuromuscular junction, with receptors for the neurotransmitter acetylcholine

motor unit

motor neuron and the group of muscle fibers it innervates

muscle fiber

a single muscle cell

muscle tension

force generated by the contraction of the muscle; tension generated during isotonic contractions and isometric contractions

muscle tone

low levels of muscle contraction that occur when a muscle is not producing movement

myoblast

muscle-forming stem cell

myofibril

long, cylindrical organelle that runs parallel within the muscle fiber and contains the sarcomeres

myofilament

thread-like muscle proteins

myogram

instrument used to measure twitch tension

myosin

protein that makes up most of the thick cylindrical myofilament within a sarcomere muscle fiber

neuromuscular junction (NMJ)

synapse between the axon terminal of a motor neuron and the section of the membrane of a muscle fiber with receptors for the acetylcholine released by the terminal

oxygen debt

amount of oxygen needed to compensate for ATP produced without oxygen during muscle contraction

perimysium

connective tissue that bundles skeletal muscle fibers into fascicles within a skeletal muscle

power stroke

action of myosin pulling actin inward (toward the M line)

pyruvic acid

product of glycolysis that can be used in aerobic respiration or converted to lactic acid

relaxation phase

period after twitch contraction when tension decreases

sarcolemma

plasma membrane of a skeletal muscle fiber

sarcomere

longitudinally, repeating functional unit of skeletal muscle, with all of the contractile and associated proteins involved in contraction

sarcopenia

age-related muscle atrophy

sarcoplasm

cytoplasm of a muscle cell

sarcoplasmic reticulum (SR)

specialized smooth endoplasmic reticulum, which stores, releases, and retrieves Ca++

skeletal muscle

striated, multinucleated muscle that requires signaling from the nervous system to trigger contraction; most skeletal muscles are referred to as voluntary muscles that move bones and produce movement

slow oxidative (SO)

muscle fiber that primarily uses aerobic respiration

smooth muscle

nonstriated, mononucleated muscle in the skin that is associated with hair follicles; assists in moving materials in the walls of internal organs, blood vessels, and internal passageways

synaptic cleft

space between a nerve (axon) terminal and a motor end-plate

T-tubule

projection of the sarcolemma into the interior of the cell

tendon

rope-shaped connective tissues that tie (anchor) muscles to bone

tetanus

a continuous fused contraction

thick filament

the thick myosin strands and their multiple heads projecting from the center of the sarcomere toward, but not all to way to, the Z-discs

thin filament

thin strands of actin and its troponin-tropomyosin complex projecting from the Z-discs toward the center of the sarcomere

tropomyosin

regulatory protein that covers myosin-binding sites to prevent actin from binding to myosin

troponin

regulatory protein that binds to actin, tropomyosin, and calcium

twitch

single contraction produced by one action potential

wave summation

addition of successive neural stimuli to produce greater contraction

11. Skeletal muscle anatomy

Muscles list:

Occipitofrontalis

Occipitofrontalis aponeurosis

Orbicularis oculi

Orbicularis oris

Zygomaticus major and minor

Buccinator

Platysma

Corrugator supercilii

Masseter

Temporalis

Genioglossus

Styloglossus

Palatoglossus

Hyoglossus

Suprahyoid

Infrahyoid

Digastric

Stylohyoid

Mylohyoid

Geniohyoid

Omohyoid

Thyrohyoid

Sternothyroid

Sternocleidomastoid

Scalene

Splenius

external oblique

internal oblique

transversus abdominis

linea alba

rectus abdominis

Diaphragm

external intercostal

internal intercostal

levator ani

Ischiococcygeus

Pubococcygeus

Iliococcygeus

Bulbospongiosus

Ischiocavernosus

external anal sphincter

compressor urethrae

sphincter urethrovaginalis

erector spinae

Iliocostalis

Longissimus

Spinalis

Transversospinalis

pectoralis minor

serratus anterior

Trapezius

rhomboid major

rhomboid minor

pectoralis major

latissimus dorsi

Deltoid

Subscapularis

Supraspinatus

Infraspinatus

teres major

teres minor

biceps brachii

Brachialis

Brachioradialis

triceps brachii

Pronator teres

Supinator

Flexor carpi radialis

Palmaris longus

Flexor carpi ulnaris

Flexor digitorum superficialis

Flexor pollicis longus

Flexor digitorum profundus

Extensor radialis longus

Extensor carpi radialis bravis

Extensor digitorum

Extensor digiti minimi

Extensor carpi ulnaris

Abductor pollicis longus

Extensor pollicies brevis

Extensor pollicis longus

Extensor indicis

Retinaculum

Flexor retinaculum

Thenar

Hypothenar

Intermediate

Iliopsoas

Gluteus maximus

Gluteus medius

Tensor fascia latae

Iliotibial tract

Piriformis

Rectus femoris

Vastus lateralis, medialis, intermedius

Sartorius

Biceps femoris

Semitendinosus

Semimembranosus

Adductor longus, brevis, magnus

Pectineus

Gracilis

Tibialis anterior

Extensor digitorum longus

Fibularis longus, brevis

Gastrocnemius

Soleus

12. Nervous tissue

absolute refractory period

period time during an action period when another action potential cannot be generated because the voltage-gated Na+ channel is inactivated

acetylcholine (ACh)

one of the most common and well studied neurotransmitters, it plays roles in all NMJs and many synapses of ANS pathways

acetylcholinesterase (AChE)

an enzyme that breaks down ACh within synapses to regulate its effect

action potential

change in voltage of a cell membrane in response to a stimulus that results in

transmission of an electrical signal; unique to neurons and muscle fibers

afferent neuron

neuron that sends nervous signals towards the brain and/ or spinal cord

anterograde transport

the transport of substances from neuron soma toward axon terminals

aspartate

a common excitatory amino acid neurotransmitter of the spinal cord among other roles

astrocyte

glial cell type of the CNS that provides support for neurons and maintains the blood-brain barrier

autonomic nervous system (ANS)

functional division of the nervous system that is responsible for homeostatic reflexes that coordinate control of cardiac and smooth muscle, as well as glandular tissue

axon

single process of the neuron that carries an electrical signal (action potential) away from the cell body toward a target cell

axon hillock

tapering of the neuron cell body that gives rise to the axon

axon terminal

end of the axon, where there are usually several branches extending toward the target cell

axoplasm

cytoplasm of an axon, which is different in composition than the cytoplasm of the neuronal cell body

biogenic amine

class of neurotransmitters that are enzymatically derived from amino acids but no longer contain a carboxyl group such as serotonin, dopamine, norepinephrine, and epinephrine

bipolar neurons

shape of a neuron with two processes extending from the neuron cell body—the axon and one dendrite

blood-brain barrier (BBB)

physiological barrier between the circulatory system and the central nervous system that establishes a privileged blood supply, restricting the flow of substances into the CNS

brain

the large organ of the CNS composed of white and gray matter, contained within the cranium and continuous with the spinal cord

calcium (Ca++) pumps

proteins that pump Ca++ ions out of the cytoplasm to the ER or extracellular space

central nervous system (CNS)

anatomical division of the nervous system located within the cranial and vertebral cavities, namely the brain and spinal cord

cerebrospinal fluid (CSF)

circulatory fluid within the CNS that is produced by ependymal cells in choroid plexuses

chemical synapse

connection between two neurons, or between a neuron and its target, where a neurotransmitter diffuses across a very short distance

cholinergic

system neurotransmitter system of acetylcholine, which includes its receptors and the

enzyme acetylcholinesterase

continuous conduction

slow propagation of an action potential along an unmyelinated axon owing to voltage-gated Na+ channels located along the entire length of the cell membrane

converging circuit

a neuron circuit by which several input neurons converge onto one neuron

current

the movement of charged particles from one area to another

dendrite

one of many branchlike processes that extends from the neuron cell body and functions as a contact for incoming signals (synapses) from other neurons or sensory cells

depolarized

change in a cell membrane potential from rest toward zero effector protein enzyme that catalyzes the generation of a new molecule, which acts as the intracellular mediator of the signal that binds to the receptor

diverging

a neuron circuit whereby one input neuron acts on several other neurons

dynein

a motor protein involved in neuronal retrograde transport

efferent neuron

neuron that sends nervous signals away from the brain and/ or spinal cord

electrical synapse

connection between two neurons, or any two electrically active cells, where ions flow

directly through channels spanning their adjacent cell membranes

enteric nervous system (ENS)

neural tissue associated with the digestive system that is responsible for nervous control through autonomic connections

enzymatic degradation

a process of regulating neurotransmitter effect by breaking it down soon after release into the synaptic cleft

ependymal cell

glial cell type in the CNS responsible for producing cerebrospinal fluid

excitatory postsynaptic potential (EPSP)

graded potential in the postsynaptic membrane that is the result of depolarization and makes an action potential more likely to occur

gamma-amino-butyric-acid (GABA)

a common inhibitory amino acid neurotransmitter of the brain among other roles

ganglion (pl. ganglia)

localized collection of neuron cell bodies in the peripheral nervous system

gated property of a channel that determines how it opens under specific conditions, such as voltage change or physical deformation

generator potential

graded potential in dendrites of a unipolar neuron which generates an action

potential in the initial segment of that cell’s axon

glial cell (aka neuroglia)

one of the various types of neural cells responsible for maintenance of nervous tissue including the support of neurons

glutamate

a common excitatory amino acid neurotransmitter of the brain among other roles

glycine

a common inhibitory amino acid neurotransmitter of the spinal cord among other roles

G-protein coupled receptors

receptors that are associated with cytoplasmic G-protein, a GTP hydrolase, that physically moves from the receptor to a effector protein resulting in the production of cAMP or cGMP (aka second messengers)

graded potential

change in the membrane potential that varies in size, depending on the size of the

stimulus that elicits it

gray matter regions of the nervous system containing cell bodies of neurons with few or no myelinated axons; actually may be more pink or tan in color, but called gray in contrast to white matter

Guillain-Barré Syndrome

a pathologic condition caused by demyelination of neurons in the PNS

hyperpolarize

state of the cell membrane when it polarizes more than the RMP

inhibitory postsynaptic potential (IPSP)

hyperpolarizing graded potentials in the postsynaptic membrane

integration

nervous system function that combines sensory perceptions and higher cognitive functions (memories, learning, emotion, etc.) to produce a response

ionotropic receptor

an ion channel gate that opens by neurotransmitter binding

kinesin

a motor protein involved in neuronal anterograde transport

leakage channel

ion channel that opens randomly and is not gated to a specific event, also known as a non-gated channel

ligand-gated channels

ion channel that opens upon neurotransmitter binding

local potential

change in membrane potential that is limited to the area nearby an open ion gate

mechanically gated channel

ion channel that opens when a physical event directly affects the structure of the protein

membrane potential

distribution of charge across the cell membrane, based on the charges of ions

metabotropic receptor

neurotransmitter receptor that involves a complex of proteins that cause

metabolic changes in a cell

microglia

cell type in the CNS that serves as the resident component of the immune system

monoamine oxidase inhibitor (MAOI)

a drug prescribed to serotonin deficient patients to potentiate the neurotransmitter effects by reducing intracellular enzymatic degradation

motor neuron

neuron that send action potentials towards muscles and glands for body movement and regulating physiology

multipolar neurons

shape of a neuron that has multiple processes—the axon and two or more dendrites

multiple sclerosis

a pathologic condition caused by progressive demyelination of neurons in the CNS

muscarinic receptor

type of acetylcholine receptor protein that is characterized by also binding to

muscarine and is a metabotropic receptor

myelin

lipid-rich insulating substance surrounding axons of some neurons

myelination

process of producing layers of myelin around neuron axons

myelin sheath

multiple layers of insulating myelin of some neuron axon regions allowing for faster transmission of electrical signals

nerve

cord-like bundle of axons located in the peripheral nervous system that transmits sensory input and response output to and from the central nervous system

nerve fiber

bundles of axons classified as either type A, B, or C fibers according to their diameter and degree of myelination

neuron

neural tissue cell that is primarily responsible for generating and propagating electrical signals into, within, and out of the nervous system

neuronal pool

a group of neurons within a nucleus serving a common function

neuropeptide

neurotransmitter of short chain (2-40) amino acids

neurosoma (aka soma)

in neurons, that portion of the cell that contains the nucleus; the cell body, as opposed to the cell processes (axons and dendrites)

neurotransmitter

chemical signal that is released from the synaptic end bulb of a neuron to cause a

change in the target cell

nicotinic receptor

type of acetylcholine receptor protein that is characterized by also binding to

nicotine and is an ionotropic receptor

Nissl body

rough ER of neurons which appears purple and granular when viewed under a microscope

nodes of Ranvier (aka neurofibril nodes)

gaps between two myelinated regions of an axon

nucleus (pl. nuclei)

in the nervous system, a localized collection of neuron cell bodies that are functionally related; a “center” of neural function

Ohm’s law

states that electrical current is directly proportional to voltage and indirectly to resistance

oligodendrocyte

glial cell type in the CNS that provides the myelin insulation for axons in tracts

parallel-after-discharge circuits

complex neural circuits in which both converging and diverging patterns are used

peripheral nervous system (PNS)

anatomical division of the nervous system that is largely outside the cranial and vertebral cavities, namely all parts except the brain and spinal cord

polarized

in relation to the electrical properties of a neuron, the state whereby the inner membrane is negatively charged compared to the outer

postsynaptic neuron

the neuron with receptors that bind neurotransmitters in the synaptic cleft

postsynaptic potential (PSP)

graded potential in the postsynaptic membrane caused by the binding of neurotransmitter to ionotropic receptors

presynaptic neuron

the neuron that secretes neurotransmitters into the synaptic cleft

process

in cells, an extension of a cell body; in the case of neurons, this includes the axon and dendrites

propagation

conduction of an action potential along the length of an axon

receptor potential

graded potential in a specialized sensory cell that directly causes the release of neurotransmitter without an intervening action potential

refractory period

time after the initiation of an action potential when another action potential cannot be generated

relative refractory period

time during the refractory period when a new action potential can only be initiated by a stronger stimulus than the current action potential because voltage-gated K+ channels are not closed

repolarized

return of the membrane potential to RMP after depolarization

resistance

the property of electricity whereby the current is impeded in some way

resting membrane potential (RMP)

the difference in voltage across a cell membrane under steady state conditions, typically -70 mV

retrograde transport

the transport of substances from axon terminals toward neuron soma

reuptake

a process of regulating neurotransmitter effect by transporting it back to the presynaptic neuron from the synaptic cleft

reverberating circuit

serving rhythmic functions, these neural circuits continue until there is an inhibitory signal

saltatory conduction

quick propagation of the action potential along a myelinated axon owing to the insulting effects of myelin necessitating voltage-gated Na+ channels only at the nodes of Ranvier

satellite cell

PNS glial cell type that provides support for neuron soma

Schwann cell (aka neurolemmocyte)

glial cell type that myelinates axons in the PNS

sensory input / sensation

nervous system function that receives information from the environment and translates it into the electrical signals of nervous tissue

sensory neuron

neurons that generate action potentials in response to specific stimuli, sending signals towards the CNS

serotonin-specific reuptake inhibitors (SSRIs)

a drug prescribed to serotonin deficient patients to potentiate the neurotransmitter effects by reducing reuptake

sodium-potassium pump

concentrates ions by pumping three Na+ ions out for every two K+ ions brought in a cell

somatic motor neuron

transmits efferent nervous signals to skeletal muscles for body movement and posture

somatic nervous system (SNS)

functional division of the nervous system that is concerned with conscious perception, voluntary movement, and skeletal muscle reflexes

somatosensory neuron

transmit afferent nervous signals regarding the body’s external environment, orientation and movement

spatial summation

combination of graded potentials across the neuronal cell membrane caused by signals from separate presynaptic elements that add up to initiate an action potential

spinal cord

organ of the CNS found within the vertebral cavity and connected with the PNS through spinal nerves; mediates reflex behaviors; relays nervous signals to and from the brain

stimulus

anything with the potential to evoke a reaction

subthreshold

graded potentials that fail to induce an action potential

summate

to add together, as in the cumulative change in postsynaptic potentials toward reaching threshold in the membrane, either across a span of the membrane or over a certain amount of time

synapse

narrow junction across which a chemical signal passes from neuron to the next, initiating a new electrical signal in the target cell

synaptic cleft

small gap between cells in a chemical synapse where neurotransmitter diffuses from the presynaptic element to the postsynaptic element

synaptic end bulb (aka synaptic bouton)

the swollen end of axon terminals

synaptic end terminal (aka synaptic terminal)

the end of an axon, opposite the soma, where neurotransmitter molecules are released into the synaptic cleft

temporal summation

combination of graded potentials at the same location on a neuron resulting in a strong signal from one input

threshold

membrane voltage at which an action potential is initiated

tract

bundle of axons in the central nervous system having the same function and point of origin

type A fibers

nerve fibers with large diameters and a high degree of myelination and therefore conduct action potentials more quickly than other fiber types

type B fibers

nerve fibers with intermediate diameters and a low degree of myelination and therefore conduct action potentials at speeds between that of type A and C fibers

type C fibers

nerve fibers with small diameters that are unmyelinated and therefore conduct action potentials more slowly than other fiber types

unipolar neurons

neurons with only one process that connects to an axon which has dendrites on one end

visceral motor neuron

transmit efferent signals to cardiac muscle, smooth muscle, and glands

visceral sensory neuron

transmit afferent nervous signals from organs other than skin, joints, muscles and the special sensory organs

voltage (aka potential energy)

the difference in electrical charge between two areas

voltage-gated channel

ion channel that opens because of a change in the charge distributed across the membrane nearby

white matter

regions of the nervous system, usually referencing the CNS,  containing mostly myelinated axons which makes the tissue appear whitedue to the high lipid content

13. General senses & spinal cord

afferent

moving toward (the central nervous system)

anterior column

white matter between the anterior horns of the spinal cord composed of many different groups of axons of both ascending and descending tracts

anterior corticospinal tract

division of the corticospinal pathway that travels through the ventral (anterior) column of the spinal cord and controls axial musculature through the medial motor neurons in the ventral (anterior) horn

anterior (ventral) horn

gray matter of the spinal cord containing multipolar lower motor neurons

arachnoid mater

middle layer of the meninges named for the spider-web–like trabeculae that extend between it and the pia mater

autonomic reflex

reflex carried by autonomic nerves with effectors consisting of smooth muscle, cardiac muscle or glands

axillary nerve

systemic nerve of the arm that arises from the brachial plexus

Babinski sign

abduction and dorsiflexion of the toes in response to testing of the plantar reflex

brachial plexus

nerve plexus associated with the lower cervical spinal nerves and first thoracic spinal nerve

brachial plexus avulsion

trauma that results in partial or complete tearing of part of the brachial plexus

Brown-Sequard hemisection

injury in which one half (left or right) of the spinal cord is severed

bulbous (Ruffini) corpuscles

encapsulated nerve endings that detect skin stretch

capsaicin

molecule that activates nociceptors by interacting with a temperature-sensitive ion channel and is the basis for “hot” sensations in spicy food

cauda equina

bundle of spinal nerve roots that descend from the lower spinal cord below the first lumbar vertebra and lie within the vertebral cavity; has the appearance of a horse’s tail

central nervous system (CNS)

anatomical division of the nervous system located within the cranial and vertebral cavities, namely the brain and spinal cord

cerebrospinal fluid (CSF)

circulatory medium within the CNS that is produced by ependymal cells in the choroid plexus filtering the blood

cervical enlargement

region of the ventral (anterior) horn of the spinal cord that has a larger population of motor neurons for the greater number of and finer control of muscles of the upper limb

cervical plexus

nerve plexus associated with the upper cervical spinal nerves

chemoreceptor

sensory receptor cell that is sensitive to chemical stimuli, such as in taste, smell, or pain

communicating rami

the autonomic branches of a spinal nerve consisting of either preganglionic or postganglionic sympathetic neurons

contralateral

word meaning “on the opposite side,” as in axons that cross the midline in a fiber tract

contralateral reflex

reflex in which receptor and effector are on opposite sides of the body

conus medullaris

the end of the spinal cord that tapers into a point

corneal reflex

protective response to stimulation of the cornea causing contraction of the orbicularis oculi muscle resulting in blinking of the eye

corticobulbar tract

connection between the cortex and the brain stem responsible for generating movement

corticospinal tract

connection between the cortex and the spinal cord responsible for generating movement

cranial nerve

one of twelve nerves connected to the brain that are responsible for sensory or motor functions of the head and neck

cranial reflex

reflex carried by cranial nerves with an integration center within the brain

crossed extensor reflex

reflex that causes limb extension and occurs simultaneous and contralateral to the withdrawal reflex

cutaneous reflex

reflex elicited by stimulating receptors located in the skin

decussate

to cross the midline, as in fibers that project from one side of the body to the other

deep tendon reflexes

clinical procedure used to test the stretch reflex in various muscles by tapping on the muscle tendon to stretch the muscle

denticulate ligaments

lateral extensions of the pia mater that stabilize the spinal cord in the vertebral canal

direct pathways

the corticospinal and corticobulbar tracts that give conscious control over movement consisting of upper motor neuron originating in the primary motor cortex and lower motor neuron located in the ventral horn or brainstem, respectively

dorsal column

white matter tracts carrying touch and proprioception sensory information and located between the dorsal horns of the spinal cord

dorsal column-medial lemniscus tract

ascending tract of the spinal cord associated with fine touch and proprioceptive sensations

dorsal ramus

the dorsal branch of a spinal nerve consisting of both sensory and motor neurons

dorsal (posterior) root

axons entering the posterior horn of the spinal cord

dorsal (posterior) root ganglion

sensory ganglion attached to the posterior nerve root of a spinal nerve

dura mater

tough, fibrous, outer layer of the meninges that is attached to the inner surface of the cranium and vertebral column and surrounds the entire CNS

effector

the structure (skeletal muscle, cardiac muscle, smooth muscle or gland) that carries out the action at the end of a reflex arc

efferent

moving away from (the central nervous system)

encapsulated ending

configuration of a sensory receptor neuron with dendrites surrounded by specialized structures to aid in transduction of a particular type of sensation, such as the lamellated corpuscles in the deep dermis and subcutaneous tissue

endoneurium

innermost layer of connective tissue that surrounds individual axons within a nerve

epidural space

space above the dura mater of the meninges

epineurium

outermost layer of connective tissue that surrounds an entire nerve

exteroceptor

sensory receptor that is positioned to interpret stimuli from the external environment, such as photoreceptors in the eye or somatosensory receptors in the skin

extrapyramidal system

pathways between the brain and spinal cord that are separate from the corticospinal tract and are responsible for modulating the movements generated through that primary pathway

fascicle

small bundles of nerve or muscle fibers enclosed by connective tissue

fasciculus cuneatus

lateral division of the dorsal column system composed of fibers from sensory neurons in the upper body

fasciculus gracilis

medial division of the dorsal column system composed of fibers from sensory neurons in the lower body

femoral nerve

systemic nerve of the anterior leg that arises from the lumbar plexus

filum terminale

thin extension of the pia mater from the caudal end of the spinal cord that helps to stabilize the spinal cord in the vertebral canal

flaccid paralysis

paralysis resulting from lower motor neuron damage in which muscles are completely relaxed

free nerve ending

configuration of a sensory receptor neuron with dendrites in the connective tissue of the organ, such as in the dermis of the skin, that are most often sensitive to chemical, thermal, and mechanical stimuli

general sense

any sensory system that is distributed throughout the body and incorporated into organs of multiple other systems, such as the walls of the digestive organs or the skin

gray matter

regions of the nervous system containing cell bodies of neurons with few or no myelinated axons; actually may be more pink or tan in color, but called gray in contrast to white matter

hair root plexus

nerve endings that are wrapped around hair follicles to detect hair movement

hemiplegia

paralysis of one side of the body

hyperreflexia

exaggeration of reflexes often due to upper motor neuron damage

hyporeflexia

decreased reflexes often due to lower motor neuron damage

indirect pathways

several complex circuits that innervate lower motor neurons and are involved in subconscious control over movement

integration (reflex) center

gray matter of the spinal cord or brain that integrates incoming sensory and other information in the control of a reflex

interoceptor

sensory receptor that is positioned to interpret stimuli from internal organs, such as stretch receptors in the wall of blood vessels

ipsilateral

word meaning on the same side, as in axons that do not cross the midline in a fiber tract

ipsilateral reflex

reflex in which receptor and effector are on the same side of the body

kinesthesia

sense of body movement based on sensations in skeletal muscles, tendons, joints, and the skin

lamellated (Pacinian) corpuscles

encapsulated nerve endings located in the deep dermis or subcutaneous layer that detect deep pressure or vibration

lateral column

white matter of the spinal cord between the posterior horn on one side and the axons from the anterior horn on the same side; composed of many different groups of axons, of both ascending and descending tracts, carrying sensory and motor commands to and from the brain

lateral corticospinal tract

division of the corticospinal pathway that travels through the lateral column of the spinal cord and controls appendicular musculature through the lateral motor neurons in the ventral (anterior) horn

lateral horn

region of the spinal cord gray matter in the thoracic and upper lumbar regions that is the central component of the sympathetic division of the autonomic nervous system

lower motor neuron

second neuron in the motor command pathway that is directly connected to the skeletal muscle

lumbar enlargement

region of the ventral (anterior) horn of the spinal cord that has a larger population of motor neurons for the greater number of muscles of the lower limb

lumbar plexus

nerve plexus associated with the lumbar spinal nerves

lumbar puncture

procedure used to withdraw CSF from the lower lumbar region of the vertebral column that avoids the risk of damaging CNS tissue because the spinal cord ends at the upper lumbar vertebrae

mechanoreceptor

receptor cell that transduces mechanical stimuli into an electrochemical signal

medial lemniscus

fiber tract of the dorsal column system that extends from the nuclei gracilis and cuneatus to the thalamus, and decussates

median nerve

systemic nerve of the arm, located between the ulnar and radial nerves

meninges

protective outer coverings of the CNS composed of connective tissue

monosynaptic reflex

rapid reflex arc where the incoming sensory neuron synapses directly on the lower motor neuron minimizing synaptic delay

muscle spindle

specialized intrafusal muscle fiber that detects stretch of a muscle

nerve plexus

network of nerves without neuronal cell bodies included formed from the ventral rami of spinal nerves

nociception

the detection of painful stimuli

nociceptor

receptor cell that senses pain stimuli

nucleus cuneatus

medullary nucleus at which first-order neurons of the dorsal column system synapse specifically from the upper body and arms

nucleus gracilis

medullary nucleus at which first-order neurons of the dorsal column system synapse specifically from the lower body and legs

obturator nerve

peripheral nerve that carries sensory information from the medial thigh and motor innervation of most adductor muscles

osmoreceptor

receptor cell that senses differences in the concentrations of bodily fluids on the basis of osmotic pressure

paraplegia

paralysis of the lower extremities

paresis

partial paralysis or weakness of a limb

patellar reflex

stretch reflex of the quadriceps muscle elicited by tapping the patellar ligament

perception

becoming aware of a stimulus

perineurium

layer of connective tissue surrounding fascicles within a nerve

peripheral nerve

nerve in the periphery distal to a nerve plexus or spinal nerve

peripheral neuropathy

damage to a peripheral nerve, spinal nerve or the nerve roots that results in sensory and or motor impairments to the region innervated by the nerve

peripheral nervous system (PNS)

anatomical division of the nervous system that is largely outside the cranial and vertebral cavities, namely all parts except the brain and spinal cord

phantom limb pain

erroneous perception of pain as originating from an amputated limb

phantom limb sensation

erroneous perception of stimuli as originating from an amputated limb

phasic sensory receptor

sensory receptors that adapt rapidly and more completely

photoreceptor

receptor cell specialized to respond to light stimuli

phrenic nerve

systemic nerve from the cervical plexus that innervates the diaphragm

pia mater

thin, innermost membrane of the meninges that directly covers the surface of the CNS

plantar reflex

cutaneous reflex elicited by scraping the plantar surface of the foot from heel to toe

polysynaptic reflex

reflex arc in which at least one interneuron lies between the afferent sensory neuron and the efferent motor neuron

posterior columns

white matter of the spinal cord that lies between the posterior horns of the gray matter, sometimes referred to as the dorsal column; composed of axons of ascending tracts that carry sensory information up to the brain

posterior (dorsal) horn

gray matter region of the spinal cord in which sensory input arrives

primary motor cortex

location of upper motor neurons in the precentral gyrus of the frontal lobe

primary somatosensory cortex

postcentral gyrus of the parietal lobe that initially receives somatosensory input from an ascending pathway from the thalamus and begins the processing that will result in conscious perception of that sensory modality

proprioception

sense of position and movement of the body

proprioceptor

receptor cell that senses changes in the position and kinesthetic aspects of the body

pyramidal decussation

location at which corticospinal tract fibers cross the midline and segregate into the anterior and lateral divisions of the pathway

pyramidal tract

the lateral and anterior corticospinal tracts

quadriplegia

paralysis of all four limbs

radial nerve

systemic nerve of the arm, the distal component of which is located near the radial bone

receptor cell

cell that transduces environmental stimuli into neural signals

reciprocal innervation

the simultaneous inhibition of all antagonist muscles during stimulation of any muscle

referred pain

when pain is perceived at a location other than the site of the painful stimulus

reflex

automatic and consistent response to a stimulus

reflex arc

reflex pathway consisting of receptor, sensory afferent neuron, integration or reflex center, motor efferent neuron and effector

reticulospinal tract

extrapyramidal connections between the brain stem and spinal cord that modulate movement, contribute to posture, and regulate muscle tone

Romberg test

clinical test of balance requiring vestibular, proprioception and visual stimuli to maintain posture

rubrospinal tract

descending motor control pathway, originating in the red nucleus, that mediates control of the limbs on the basis of cerebellar processing

sacral plexus

nerve plexus associated with the lower lumbar and sacral spinal nerves

sciatic nerve

systemic nerve from the sacral plexus that is a combination of the tibial and fibular nerves and extends across the hip joint and gluteal region into the upper posterior leg

sciatica

painful condition resulting from inflammation or compression of the sciatic nerve or any of the spinal nerves that contribute to it

sensation

nervous system function that receives information from the environment and translates it into the electrical signals of nervous tissue

sensory adaptation

the gradual decrease in responsiveness of a receptor to a constant stimulus

sensory modality

a particular system for interpreting and perceiving environmental stimuli by the nervous system such as light, sound, touch, temperature etc…

sensory transduction

process of changing an environmental stimulus into the electrochemical signals of the nervous system

shoulder dystocia

condition where a baby’s shoulders get stuck during a vaginal delivery

somatic nervous system (SNS)

functional division of the nervous system that is concerned with conscious perception, voluntary movement, and skeletal muscle reflexes

somatic reflex

reflexes with effectors consisting of skeletal muscle

somatosensation

general senses related to the body, usually thought of as the senses of touch, which would include pain, temperature, and proprioception

spastic paralysis

paralysis resulting from damage to upper motor neurons in which muscle tension  is maintained and may spasm

special sense

any sensory system associated with a specific organ structure, namely smell, taste, sight, hearing, and balance

spina bifida

caudal neural tube defect resulting in exposure of the spinal cord

spinal nerve

one of 31 nerves connected to the spinal cord

spinal reflex

reflex carried by spinal nerves with an integration center within the spinal cord

spinal segment

a region of the spinal cord that supplies dorsal and ventral roots for one spinal nerve

spinothalamic tract

ascending tract of the spinal cord associated with pain and temperature sensations

stimulus

an event in the external or internal environment that registers as activity in a sensory neuron

stretch reflex

response to activation of the muscle spindle stretch receptor that causes contraction of the muscle to maintain a constant length

subarachnoid space

space between the arachnoid mater and pia mater that contains CSF and the fibrous connections of the arachnoid trabeculae

sympathetic chain ganglia

autonomic ganglia in a chain along the anterolateral aspect of the vertebral column that are responsible for contributing to homeostatic mechanisms of the autonomic nervous system

tactile (Meissner’s) corpuscles

encapsulated nerve endings located in the dermal papilla that detect discriminative touch and vibration

tactile epithelial cells (Merkel cells)

cells located in the stratum basale of the epidermis that detect light touch

tectospinal tract

extrapyramidal connections between the superior colliculus and spinal cord

tendon organ (Golgi tendon organ)

encapsulated receptor within muscle tendons that detect tension

tendon reflex (Golgi tendon reflex)

inhibitory reflex that uses the tendon organ as a receptor to prevent damage to muscle or tendon by stimulating muscle relaxation as a response to excessive force

thermoreceptor

sensory receptor specialized for temperature stimuli

tonic sensory receptors

sensory receptors that adapt slowly and only partially

two-point discrimination

the ability to discern two separate points touching the skin as being separate

ulnar nerve

systemic nerve of the arm located close to the ulna, a bone of the forearm

upper motor neuron

first neuron in the motor command pathway with its cell body in the cerebral cortex that synapses on the lower motor neuron in the spinal cord

ventral column

white matter of the spinal cord located between the ventral horns

ventral ramus

the ventral branch of a spinal nerve consisting of both sensory and motor neurons

ventral (anterior) root

axons emerging from the anterior or lateral horns of the spinal cord

vestibulospinal tract

extrapyramidal connections between the vestibular nuclei in the brain stem and spinal cord that modulate movement and contribute to balance on the basis of the sense of equilibrium

visceral sense

sense associated with the internal organs

Wallerian degeneration

active process of retrograde degeneration of the distal end of an axon after it has been severed

white matter

regions of the nervous system containing mostly myelinated axons, making the tissue appear white because of the high lipid content of myelin

withdrawal reflex (flexor withdrawal reflex)

reflex in which a painful stimulus causes withdrawal of the injured body part

14. Brain

abducens nerve

sixth cranial nerve; responsible for contraction of one of the extraocular muscles

amygdala

nucleus deep in the temporal lobe of the cerebrum that is related to memory and emotional behavior

anterograde amnesia

type of memory loss that occurs when a person can’t form new memories

aphasia

loss of ability to understand or express speech, caused by brain damage

arachnoid granulation

outpocket of the arachnoid membrane into the dural sinuses that allows for reabsorption of CSF into the blood

arachnoid mater

middle layer of the meninges named for the spider-web–like trabeculae that extend between it and the pia mater

arachnoid trabeculae

filaments between the arachnoid and pia mater within the subarachnoid space

arbor vitae

the cerebellar white matter, so called for its branched, tree-like appearance

astrocytes

glial cells that envelop the capillaries in the brain

basal nuclei

nuclei of the cerebrum (with a few components in the upper brain stem and diencephalon) that are responsible for assessing cortical movement commands and comparing them with the general state of the individual through broad modulatory activity of dopamine neurons; largely related to motor functions, as evidenced through the symptoms of Parkinson’s and Huntington’s diseases

basilar artery

blood vessel from the merged vertebral arteries that runs along the dorsal surface of the brain stem

blood-brain barrier

physical barrier between the neurons and circulating blood

brain stem

region of the adult brain that includes the midbrain, pons, and medulla oblongata and develops from the mesencephalon, metencephalon, and myelencephalon of the embryonic brain

Broca’s area

region of the frontal lobe associated with the motor commands necessary for speech production and located only in the cerebral hemisphere responsible for language production, which is the left side in approximately 95 percent of the population

caudate

nucleus deep in the cerebrum that is part of the basal nuclei; along with the putamen, it is part of the striatum

central canal

hollow space within the spinal cord that is the remnant of the center of the neural tube

cerebellar cortex

receives information from most parts of the body

cerebellar hemispheres

two divisions of the cerebellum on either side of the vermis

cerebellar nuclei

deep cerebellar nuclei

cerebellum

region of the adult brain connected primarily to the pons that developed from the metencephalon (along with the pons) and is largely responsible for comparing information from the cerebrum with sensory feedback from the periphery through the spinal cord

cerebral aqueduct

connection of the ventricular system between the third and fourth ventricles located in the midbrain

cerebral cortex

outer gray matter covering the forebrain, marked by wrinkles and folds known as gyri and sulci

cerebral hemisphere

one half of the bilaterally symmetrical cerebrum

cerebral peduncles

white matter corticospinal tracts that connect the upper motor neurons of the primary motor cortex to the lower motor neurons in the spinal cord

cerebrospinal fluid

clear liquid produced within spaces in the brain called ventricles

cerebrum

region of the adult brain that develops from the telencephalon and is responsible for higher neurological functions such as memory, emotion, and consciousness

choroid plexus

specialized structures containing ependymal cells lining blood capillaries that filter blood to produce CSF in the four ventricles of the brain

circle of Willis

unique anatomical arrangement of blood vessels around the base of the brain that maintains perfusion of blood into the brain even if one component of the structure is blocked or narrowed

corpora quadrigemina

superior and inferior colliculi that are parts of the visual and the auditory pathways respectively

corpus callosum

large white matter structure that connects the right and left cerebral hemispheres

corpus striatum

major input site of the basal ganglia (or basal nuclei)

cranial nerve

one of twelve nerves connected to the brain that are responsible for sensory or motor functions of the head and neck

decussation

when fibers cross from one side of a structure to the other side of a structure

diencephalon

region of the adult brain that retains its name from embryonic development and includes the thalamus and hypothalamus

dopamine

a type of monoamine neurotransmitter

dura mater

tough, fibrous, outer layer of the meninges that is attached to the inner surface of the cranium and vertebral column and surrounds the entire CNS

dural venous sinus

a group of sinuses or blood channels that drains venous blood circulating from the cranial cavity

ectoderm

outermost layer of cells or tissue of an embryo in early development, or the parts derived from this, which include the epidermis and nerve tissue

endoderm

innermost embryonic germ layer from which most of the digestive system and lower respiratory system derive

epidural space

area between the dura mater and the vertebral wall, containing fat and small blood vessels

epithalamus

region of the diecephalon containing the pineal gland

extraocular muscles

six skeletal muscles that control eye movement within the orbit

facial nerve

seventh cranial nerve; responsible for contraction of the facial muscles and for part of the sense of taste, as well as causing saliva production

fascicle

small bundles of nerve or muscle fibers enclosed by connective tissue

flocculonodular lobe

area of the cerebellum that receives vestibular and visual information

folia

gyrus of the cerebellar cortex

foramen magnum

large opening in the occipital bone of the skull through which the spinal cord emerges and the vertebral arteries enter the cranium

forebrain

anterior region of the adult brain that develops from the prosencephalon and includes the cerebrum and diencephalon

fourth ventricle

the portion of the ventricular system that is in the region of the brain stem and opens into the subarachnoid space through the median and lateral apertures

frontal lobe

region of the cerebral cortex directly beneath the frontal bone of the cranium

ganglion

localized collection of neuron cell bodies in the peripheral nervous system

globus pallidus

nuclei deep in the cerebrum that are part of the basal nuclei and can be divided into the internal and external segments

glossopharyngeal nerve

ninth cranial nerve; responsible for contraction of muscles in the tongue and throat and for part of the sense of taste, as well as causing saliva production

gray matter

regions of the nervous system containing cell bodies of neurons with few or no myelinated axons; actually may be more pink or tan in color, but called gray in contrast to white matter

gyrus

ridge formed by convolutions on the surface of the cerebrum or cerebellum

hindbrain

posterior region of the adult brain that develops from the rhombencephalon and includes the pons, medulla oblongata, and cerebellum

hydrocephalus

blockage in the CSF circulation

hippocampus

gray matter deep in the temporal lobe that is very important for long-term memory formation

hypoglossal nerve

twelfth cranial nerve; responsible for contraction of muscles of the tongue

hypothalamus

major region of the diencephalon that is responsible for coordinating autonomic and endocrine control of homeostasis

indirect pathway

connections within the basal nuclei from the striatum through the globus pallidus external segment and subthalamic nucleus to the globus pallidus internal segment/substantia nigra pars compacta that result in inhibition of the thalamus to decrease cortical control of movement

inferior colliculus

half of the midbrain tectum that is part of the brain stem auditory pathway

infundibulum

hollow stalk which connects the hypothalamus and the posterior pituitary gland

internal capsule

two-way tract for the transmission of information to and from the cerebral cortex

internal carotid artery

branch from the common carotid artery that enters the cranium and supplies blood to the brain

interventricular foramina

openings between the lateral ventricles and third ventricle allowing for the passage of CSF

insula

brain region that process taste, smell, sound, visceral and body surface sensations, and emotions such as empathy

jugular veins

blood vessels that return “used” blood from the head and neck

kinesthesia

general sensory perception of movement of the body

lateral apertures

pair of openings from the fourth ventricle to the subarachnoid space on either side and between the medulla and cerebellum

lateral sulcus

surface landmark of the cerebral cortex that marks the boundary between the temporal lobe and the frontal and parietal lobes

lateral ventricles

portions of the ventricular system that are in the region of the cerebrum

limbic cortex

collection of structures of the cerebral cortex that are involved in emotion, memory, and behavior and are part of the larger limbic system

limbic system

structures at the edge (limit) of the boundary between the forebrain and hindbrain that are most associated with emotional behavior and memory formation

longitudinal fissure

large separation along the midline between the two cerebral hemispheres

lumbar puncture

procedure used to withdraw CSF from the lower lumbar region of the vertebral column that avoids the risk of damaging CNS tissue because the spinal cord ends at the upper lumbar vertebrae

median aperture

singular opening from the fourth ventricle into the subarachnoid space at the midline between the medulla and cerebellum

medulla oblongata

lowest portion of the brainstem

melatonin

amino acid–derived hormone that is secreted in response to low light and causes drowsiness

meninges

protective outer coverings of the CNS composed of connective tissue

meningitis

inflammation of the meninges

meningeal layer

dense fibrous membrane that passes through the foramen magnum and is continuous with the dura mater of the spinal cord

mesencephalon

primary vesicle of the embryonic brain that does not significantly change through the rest of embryonic development and becomes the midbrain

mesoderm

middle layer of the three germ layers that develops during gastrulation in the very early development of the embryo of most animals

metencephalon

secondary vesicle of the embryonic brain that develops into the pons and the cerebellum

midbrain

middle region of the adult brain that develops from the mesencephalon

myelencephalon

secondary vesicle of the embryonic brain that develops into the medulla

nerve

cord-like bundle of axons located in the peripheral nervous system that transmits sensory input and response output to and from the central nervous system

nerve plexus

network of nerves without neuronal cell bodies included

neural crest

tissue that detaches from the edges of the neural groove and migrates through the embryo to develop into peripheral structures of both nervous and non-nervous tissues

neural plate

plate of ectoderm along the dorsal midline of the early vertebrate embryo that gives rise to the neural tube and neural crests

neural fold

elevated edge of the neural groove

neural groove

region of the neural plate that folds into the dorsal surface of the embryo and closes off to become the neural tube

neural plate

thickened layer of neuroepithelium that runs longitudinally along the dorsal surface of an embryo and gives rise to nervous system tissue

neural tube

precursor to structures of the central nervous system, formed by the invagination and separation of neuroepithelium

neuraxis

central axis to the nervous system, from the posterior to anterior ends of the neural tube; the inferior tip of the spinal cord to the anterior surface of the cerebrum

nuclei

cluster of neurons in the central nervous system, located deep within the cerebral hemispheres and brainstem

occipital lobe

region of the cerebral cortex directly beneath the occipital bone of the cranium

occipital sinuses

dural sinuses along the edge of the occipital lobes of the cerebrum

oculomotor nerve

third cranial nerve; responsible for contraction of four of the extraocular muscles, the muscle in the upper eyelid, and pupillary constriction

olfaction

special sense responsible for smell, which has a unique, direct connection to the cerebrum

olfactory nerve

first cranial nerve; responsible for the sense of smell

optic nerve

second cranial nerve; responsible for visual sensation

parietal lobe

region of the cerebral cortex directly beneath the parietal bone of the cranium

parieto-occipital sulcus

groove in the cerebral cortex representing the border between the parietal and occipital cortices

perineurium

layer of connective tissue surrounding fascicles within a nerve

periosteal layer

a layer of periosteum that covers the inner surface of the skull

peripheral nervous system

refers to parts of the nervous system outside the brain and spinal cord

pia mater

thin, innermost membrane of the meninges that directly covers the surface of the CNS

pineal gland

endocrine gland that secretes melatonin, which is important in regulating the sleep-wake cycle

pyramids

fiber bundles in the medulla that appear triangular and contain motor fibers, the majority of which are part of the corticospinal tract

pituitary gland

bean-sized organ suspended from the hypothalamus that produces, stores, and secretes hormones in response to hypothalamic stimulation (also called hypophysis)

plexus

network of nerves or nervous tissue

pons

part of the brainstem, a structure that links the brain to the spinal cord

postcentral gyrus

primary motor cortex located in the frontal lobe of the cerebral cortex

posterolateral sulcus

feature of the posterior spinal cord marking the entry of posterior nerve roots and the separation between the posterior and lateral columns of the white matter

precentral gyrus

ridge just posterior to the central sulcus, in the parietal lobe, where somatosensory processing initially takes place in the cerebrum

prefrontal lobe

specific region of the frontal lobe anterior to the more specific motor function areas, which can be related to the early planning of movements and intentions to the point of being personality-type functions

premotor area

region of the frontal lobe responsible for planning movements that will be executed through the primary motor cortex

primary vesicle

initial enlargements of the anterior neural tube during embryonic development that develop into the forebrain, midbrain, and hindbrain

proprioception

general sensory perceptions providing information about location and movement of body parts; the “sense of the self”

prosencephalon

primary vesicle of the embryonic brain that develops into the forebrain, which includes the cerebrum and diencephalon

putamen

nucleus deep in the cerebrum that is part of the basal nuclei; along with the caudate, it is part of the striatum

reticular formation

diffuse region of gray matter throughout the brain stem that regulates sleep, wakefulness, and states of consciousness

retrograde amnesia

amnesia where a person can’t recall memories that were formed before the event that caused the amnesia

rhombencephalon

primary vesicle of the embryonic brain that develops into the hindbrain, which includes the pons, cerebellum, and medulla

secondary vesicle

five vesicles that develop from primary vesicles, continuing the process of differentiation of the embryonic brain

septum pellucidum

thin membrane located at the midline of the brain between the two cerebral hemispheres

sigmoid sinuses

dural sinuses that drain directly into the jugular veins

somatosensation

general senses related to the body, usually thought of as the senses of touch, which would include pain, temperature, and proprioception

spinal nerve

one of 31 nerves connected to the spinal cord

straight sinus

dural sinus that drains blood from the deep center of the brain to collect with the other sinuses

striatum

the caudate and putamen collectively, as part of the basal nuclei, which receive input from the cerebral cortex

subarachnoid space

space between the arachnoid mater and pia mater that contains CSF and the fibrous connections of the arachnoid trabeculae

subcortical nucleus

all the nuclei beneath the cerebral cortex, including the basal nuclei and the basal forebrain

substantia nigra pars compacta

nuclei within the basal nuclei that release dopamine to modulate the function of the striatum; part of the motor pathway

substantia nigra pars reticulata

nuclei within the basal nuclei that serve as an output center of the nuclei; part of the motor pathway

subthalamus

nucleus within the basal nuclei that is part of the indirect pathway

sulcus

groove formed by convolutions in the surface of the cerebral cortex

superior colliculus

half of the midbrain tectum that is responsible for aligning visual, auditory, and somatosensory spatial perceptions

superior sagittal sinus

dural sinus that runs along the top of the longitudinal fissure and drains blood from the majority of the outer cerebrum

tectum

region of the midbrain, thought of as the roof of the cerebral aqueduct, which is subdivided into the inferior and superior colliculi

tegmentum

region of the midbrain, thought of as the floor of the cerebral aqueduct, which continues into the pons and medulla as the floor of the fourth ventricle

telencephalon

secondary vesicle of the embryonic brain that develops into the cerebrum

temporal lobe

region of the cerebral cortex directly beneath the temporal bone of the cranium

thalamus

major region of the diencephalon that is responsible for relaying information between the cerebrum and the hindbrain, spinal cord, and periphery

third ventricle

portion of the ventricular system that is in the region of the diencephalon

tract

bundle of axons in the central nervous system having the same function and point of origin

transverse sinuses

dural sinuses that drain along either side of the occipital–cerebellar space

trigeminal ganglion

sensory ganglion that contributes sensory fibers to the trigeminal nerve

trigeminal nerve

fifth cranial nerve; responsible for cutaneous sensation of the face and contraction of the muscles of mastication

trochlear nerve

fourth cranial nerve; responsible for contraction of one of the extraocular muscles

vagus nerve

tenth cranial nerve; responsible for the autonomic control of organs in the thoracic and upper abdominal cavities

ventricles

remnants of the hollow center of the neural tube that are spaces for cerebrospinal fluid to circulate through the brain

vermis

unpaired medial structure that separates the cerebellar hemispheres

vertebral arteries

arteries that ascend along either side of the vertebral column through the transverse foramina of the cervical vertebrae and enter the cranium through the foramen magnum

vestibulocochlear nerve

eighth cranial nerve; responsible for the sensations of hearing and balance

Wernicke’s area

region of the brain that contains motor neurons involved in the comprehension of speech

white matter

regions of the nervous system containing mostly myelinated axons, making the tissue appear white because of the high lipid content of myelin

15. Special senses

PHYL 142

16. Autonomic Nervous System

Review for glossary terms

17. Endocrine system

acromegaly

disorder in adults caused when abnormally high levels of GH trigger growth of bones in the face, hands, and feet

adenylyl cyclase

membrane-bound enzyme that converts ATP to cyclic AMP, creating cAMP, as a result of G-protein activation

adiponectin

Protein hormone primarily produced by adipose (fat) tissue that reverses insulin resistance by increasing cellular insulin sensitivity, and also lowers inflammation

adrenal cortex

outer region of the adrenal glands consisting of multiple layers of epithelial cells and capillary networks that produces mineralocorticoids and glucocorticoids

adrenal glands

endocrine glands located at the top of each kidney that are important for the regulation of the stress response, blood pressure and blood volume, water homeostasis, and electrolyte levels

adrenal medulla

inner layer of the adrenal glands that plays an important role in the stress response by producing epinephrine and norepinephrine

adrenocorticotropic hormone (ACTH)

anterior pituitary hormone that stimulates the adrenal cortex to secrete corticosteroid hormones (also called corticotropin)

alarm reaction

the short-term stress, or the fight-or-flight response, of stage one of the general adaptation syndrome mediated by the hormones epinephrine and norepinephrine

aldosterone

hormone produced and secreted by the adrenal cortex that stimulates sodium and fluid retention and increases blood volume and blood pressure

alpha cell

pancreatic islet cell type that produces the hormone glucagon

amine hormones

hormones that are made from amino acids and contain a −NH3+ chemical group

Anabolism

Building of larger molecules from smaller ones

Androgens

Class of sex steroid hormones that includes testosterone, primary sex hormone in males

angiotensin-converting enzyme

the enzyme that converts angiotensin I to angiotensin II

angiotensinogen

Protein secreted by the liver that is eventually converted into angiotensin II, which has more potent effects on blood pressure

anterior pituitary

Anterior lobe of the pituitary gland that secretes hormones in response to releasing hormones from the hypothalamus (also called adenohypophysis)

antidiuretic hormone (ADH)

hypothalamic hormone that is stored by the posterior pituitary and that signals the kidneys to reabsorb water (also called vasopressin or arginine vasopressin)

atrial natriuretic peptide (ANP)

peptide hormone produced by the walls of the atria in response to high blood pressure, blood volume, or blood sodium that reduces the reabsorption of sodium and water in the kidneys and promotes vasodilation

autocrine

chemical signal that elicits a response in the same cell that secreted it

beta cell

pancreatic islet cell type that produces the hormone insulin

B-type natriuretic peptide (BNP)

peptide hormone produced by the walls of the ventricles of the heart in response to high blood pressure, blood volume, or blood sodium that reduces the reabsorption of sodium and water in the kidneys and promotes vasodilation (also called brain natriuretic peptide, although this is misleading as the heart is the main source of BNP in the human body)

calcitonin

peptide hormone produced and secreted by the parafollicular cells (C cells) of the thyroid gland that functions to decrease blood calcium levels

calcitriol

active form of vitamin D produced by the kidneys that activates vitamin D receptors and genes controlled by those receptors

catabolism

Breakdown of molecules into smaller molecules or energy

cholecystokinin

peptide hormone released from the small intestine that promotes secretion of pancreatic enzymes and release of bile from the gallbladder

chromaffin

neuroendocrine cells of the adrenal medulla

circadian rhythm

Approximately 24-hour cycle of physiological changes that occur in part due to neural stimuli  daily hormonal fluctuations

circulating hormones

hormones secreted into the extracellular fluid and diffuse into the blood or lymph, where they can be carried throughout the body

colloid

viscous fluid in the central cavity of thyroid follicles, containing the glycoprotein thyroglobulin

cortisol

glucocorticoid important in gluconeogenesis, the catabolism of glycogen, and downregulation of the immune system

cyclic adenosine monophosphate (cAMP)

second messenger that, in response to adenylyl cyclase activation, triggers a phosphorylation cascade

delta cell

minor cell type in the pancreas that secretes the hormone somatostatin

diabetes mellitus

condition caused by destruction or dysfunction of the beta cells of the pancreas or cellular resistance to insulin that results in abnormally high blood glucose levels

diabetogenic effect

Elevated blood glucose levels caused by a conditon

eicosanoid

Type of lipid-derived molecule derived from arachadonic acid that acts primarily as paracrine factors

endocrine gland

tissue or organ that secretes hormones into the blood and lymph without ducts such that they may be transported to organs distant from the site of secretion

endocrine system

cells, tissues, and organs that secrete hormones as a primary or secondary function and play an integral role in normal bodily processes

epinephrine

primary and most potent catecholamine hormone secreted by the adrenal medulla in response to short-term stress; also called adrenaline

erythropoietin (EPO)

protein hormone secreted in response to low oxygen levels that triggers the bone marrow to produce red blood cells

estrogens

class of predominantly female sex hormones important for the development and growth of the female reproductive tract, secondary sex characteristics, the female reproductive cycle, and the maintenance of pregnancy

exocrine system

cells, tissues, and organs that secrete substances directly to target tissues via glandular ducts

fibroblast growth factor 23 (FGF23)

Protein hormone produced by osteocytes that responds to increased blood levels of vitamin D3 or phosphate and functions to increase phosphorus excretion and decrease calcitriol synthesis

first messenger

hormone that binds to a cell membrane hormone receptor and triggers activation of a second messenger system

follicle-stimulating hormone (FSH)

anterior pituitary hormone that stimulates the production and maturation of sex cells

G protein

protein associated with a cell membrane hormone receptor that initiates the next step in a second messenger system upon activation by hormone–receptor binding

gastrin

peptide hormone secreted in response to stomach distention that stimulates the release of hydrochloric acid

general adaptation syndrome (GAS)

the human body’s three-stage response pattern to short- and long-term stress

gigantism

disorder in children caused when abnormally high levels of GH prompt excessive growth

glucagon

pancreatic hormone that stimulates the catabolism of glycogen to glucose, thereby increasing blood glucose levels

glucocorticoids

hormones produced by the zona fasciculata of the adrenal cortex that influence glucose metabolism

Gluconeogenesis

Conversion of organic nutrients into newly synthesized glucose

glucose-dependent insulinotropic peptide (GIP)

(formerly gastric inhibitory peptide) hormone secreted by the small intestine that stimulates increased insulin secretion

Glycogenolysis

Process of catabolizing and converting stored glycogen into glucose

goiter

enlargement of the thyroid gland either as a result of iodine deficiency or hyperthyroidism

Gonad

Reproductive organ (ovary in females, testis in males) that produces sex cells (ovum in females, sperm in males)

gonadotropin-releasing hormone (GnRH)

hormone produced and secreted by the hypothalamus that stimulates production of gonadotropins

gonadotropins

hormones that regulate the function of the gonads, namely follicle-stimulating hormone (FSH) and luteinizing hormone (LH)

goiter

Abnormal growth and swelling of the thyroid gland caused by problems with iodine or thyroid function

Graves’ disease

Condition where an autoimmune reaction produces antibodies that act like TSH and cause overproduction of thyroid hormones leading to hyperthyroidism

growth hormone (GH)

anterior pituitary hormone that promotes tissue building and influences nutrient metabolism (also called somatotropin)

growth hormone deficiency (GHD)

disorder in children caused when abnormally low levels of GH result in delayed growth and short stature (also called pituitary dwarfism)

growth hormone-releasing hormone (GHRH)

Hormone secreted by the hypothalamus that triggers the release of growth hormone from the anterior pituitary

growth hormone-inhibiting hormone (GHIH)

Inhibitory hormone that inhibits the release of growth hormone and other hormones, including thyroid-stimulating hormone and prolactin (also called somatostatin)

hepcidin

Hormone secreted by the liver that regulates iron levels in blood plasma by blocking the release of iron from cells into the plasma and reducing dietary absorption of iron

hormone

secretion of an endocrine organ that travels via the bloodstream or lymphatics to induce a response in target cells or tissues in another part of the body

hormone receptor

protein within a cell or on the cell membrane that binds a hormone, initiating the target cell response

hormone-receptor complex

Structure formed when a hormone binds to its hormone receptor

human chorionic gonadotropin (hCG)

Hormone produced by the placenta that promotes progesterone synthesis and reduces the mother’s immune function to protect the fetus from immune rejection.

human placental lactogen (hPL)

Hormone produced by the placenta that prepares mammary glands for lactation

humoral

Related to body fluids

hyperglycemia

abnormally high blood glucose levels

hyperparathyroidism

disorder caused by overproduction of PTH that results in abnormally elevated blood calcium

hyperthyroidism

clinically abnormal, elevated level of thyroid hormone in the blood; characterized by an increased metabolic rate, excess body heat, sweating, diarrhea, weight loss, and increased heart rate

hypoparathyroidism

disorder caused by underproduction of PTH that results in abnormally low blood calcium

hypophyseal portal system

network of blood vessels that enables hypothalamic hormones to travel into the anterior lobe of the pituitary without entering the systemic circulation

hypothalamic-pituitary-adrenal (HPA) axis

Endocrine control system involving the hypothalamus, pituitary gland, and adrenal cortex, the hormones secreted by those glands, and regulation of adrenal cortex steroid production by those hormones

hypothalamus

region of the diencephalon inferior to the thalamus that functions in neural and endocrine signaling

hypothyroidism

clinically abnormal, low level of thyroid hormone in the blood; characterized by low metabolic rate, weight gain, cold extremities, constipation, and reduced mental activity

infundibulum

stalk containing vasculature and neural tissue that connects the pituitary gland to the hypothalamus (also called the pituitary stalk)

inhibin

hormone secreted by the male and female gonads that inhibits FSH production by the anterior pituitary

inhibiting hormone

Hormone that prevents or decrease the release of other hormones

insulin

pancreatic hormone that enhances the cellular uptake and utilization of glucose, thereby decreasing blood glucose levels

insulin-like growth factor 1 (IGF-1)

protein that enhances cellular proliferation, inhibits apoptosis, and stimulates the cellular uptake of amino acids for protein synthesis (also, somatomedin)

Ketoacidosis

Abnormally high levels of acid in the blood caused by increased levels of ketone bodies leptin

protein hormone secreted by adipose tissues in response to food consumption that promotes satiety

lipid-soluble hormones

hydrophobic hormones that easily dissolve in fats and oils, and tend to dissolve poorly in water-based fluids

Lipolysis

Catabolism of triglycerides into free fatty acids and glycerol

local hormones

hormones that act upon neighboring cells or the original cell that secreted them

luteinizing hormone (LH)

anterior pituitary hormone that triggers ovulation and the production of ovarian hormones, and the production of testosterone

Melanocyte-stimulating hormone

Hormone secreted by the intermediate zone of the pituitary gland that increase melanocyte production of melanin

melatonin

amino acid–derived hormone that is secreted in response to low light and causes drowsiness

milk ejection reflex

Process occurring in breastfeeding where an infant’s suckling triggers the movement of milk from breast alveoli to milk ducts that eject milk into the infant’s mouth (also called let-down reflex)

mineralocorticoids

hormones produced by the zona glomerulosa cells of the adrenal cortex that influence fluid and electrolyte balance

negative feedback

In the endocrine system, a situation in which an initial change triggers the release of a hormone that lessens or returns the initial change back to its normal or starting state

neonatal hypothyroidism

Thyroid hormone deficiency present at birth and can result in problems with physical and intellectual growth and development (also congenital hypothyroidism, cretinism (outdated))

nitric oxide (NO)

gas that can act as a neurotransmitter, paracrine factor, and hormone

norepinephrine

secondary catecholamine hormone secreted by the adrenal medulla in response to short-term stress; also called noradrenaline

osmoreceptor

hypothalamic sensory receptor that is stimulated by changes in solute concentration (osmotic pressure) in the blood

osteocalcin

Hormone produced by osteoblasts that stimulates the pancreas to increase insulin production

oxytocin

hypothalamic hormone stored in the posterior pituitary gland and important in stimulating uterine contractions in labor, milk ejection during breastfeeding, and feelings of attachment (produced by males and females)

pancreas

organ with both exocrine and endocrine functions located posterior to the stomach that is important for digestion and the regulation of blood glucose

pancreatic islets

specialized clusters of pancreatic cells that have endocrine functions; also called islets of Langerhans

Pancreatic polypeptide (PP)

Hormone that regulates endocrine and exocrine functions of the pancreas, as well as liver glycogen metabolism and gastrointestinal secretions

Pancreatic polypeptide cells

(formerly gamma cells or F cells) Cells in pancreatic islets that secrete pancreatic polypeptide

paracrine

chemical signal that elicits a response in neighboring cells; also called paracrine factor

parathyroid glands

small, round glands embedded in the posterior thyroid gland that produce parathyroid hormone (PTH)

parathyroid hormone (PTH)

peptide hormone produced and secreted by the parathyroid glands in response to low blood calcium levels

peptide hormone

Hormone that is made from a relatively short polypeptide chain made out of amino acids

phosphodiesterase (PDE)

cytosolic enzyme that deactivates and degrades cAMP

phosphorylation cascade

signaling event in which multiple protein kinases phosphorylate the next protein substrate by transferring a phosphate group from ATP to the protein

pineal gland

endocrine gland that secretes melatonin, which is important in regulating the sleep-wake cycle

pinealocyte

cell of the pineal gland that produces and secretes the hormone melatonin

pituitary gland

bean-sized organ suspended from the hypothalamus that produces, stores, and secretes hormones in response to hypothalamic stimulation (also called hypophysis)

positive feedback

In the endocrine system, a situation in which a stimulus or change triggers the release of a hormone, which increases and exaggerates the change, eventually resulting in amplification of the initial change and hormone levels

posterior pituitary

Posterior portion of the pituitary gland made up of neural tissue (also called neurohypophysis)

PP cell

minor cell type in the pancreas that secretes the hormone pancreatic polypeptide

protein hormone

Hormone that is made from a longer polypeptide chain as compared to relatively shorter peptide hormones

progesterone

predominantly female sex hormone important in regulating the female reproductive cycle and the maintenance of pregnancy

prolactin (PRL)

anterior pituitary hormone that promotes development of the mammary glands and the production of breast milk

protein kinase

enzyme that initiates a phosphorylation cascade upon activation

relaxin

Hormone produced by the placenta and ovaries that softens the fibrocartilage of the pubic symphysis, allowing it and the pelvic girdle to widen for childbirth

releasing hormone

Hormone secreted by the hypothalamus that targets endocrine cells in the anterior pituitary, which secretes a different hormone in response

renin-angiotensin-aldosterone system

Endocrine control system involving hormones such as angiotensin II and aldosterone that work together to increase blood pressure and volume

second messenger

molecule that initiates a signaling cascade in response to hormone binding on a cell membrane receptor and activation of a G protein

secretin

peptide hormone that stimulates the release of bicarbonate from the pancreas

somatostatin

Inhibitory hormone that inhibits the release multiple hormones, including growth hormone, thyroid-stimulating hormone, and prolactin (also called growth hormone-inhibiting hormone)

stage of exhaustion

stage three of the general adaptation syndrome; the body’s long-term response to stress mediated by the hormones of the adrenal cortex

stage of resistance

stage two of the general adaptation syndrome; the body’s continued response to stress after stage one diminishes

Steroid hormone

hormone that is originally made from cholesterol and tends to be lipid-soluble and dissolves poorly in water

sympathomedullary (SAM) pathway

Pathway by which nerve impulses travel along sympathetic nerve fibers from the hypothalamus and eventually to the adrenal medulla

testosterone

steroid hormone secreted by the testes and important in the maturation of sperm cells, growth and development of the reproductive system, and the development of secondary sex characteristics

thrombopoietin

Hormone produced by the liver that stimulates platelet production

thymosins

hormones produced and secreted by the thymus that play an important role in the development and differentiation of T cells

thymus

organ that is involved in the development and maturation of T-cells and is particularly active during infancy and childhood

thyroid gland

large endocrine gland responsible for the synthesis of thyroid hormones

thyroid-stimulating hormone (TSH)

anterior pituitary hormone that triggers secretion of thyroid hormones by the thyroid gland (also called thyrotropin)

thyroxine

(also, tetraiodothyronine, T4) amino acid–derived thyroid hormone that is more abundant but less potent than T3 and often converted to T3 by target cells

thyrotropin-releasing hormone (TRH)

Hormone secreted by the hypothalamus that stimulates the pituitary gland to secrete thyroid-stimulating hormone

triiodothyronine

(also, T3) amino acid–derived thyroid hormone that is less abundant but more potent than T4

trophic hormone

hormones that affect the growth, function, or nutrition of other endocrine cells

tropic hormone

Hormone that stimulates or inhibits the function of other endocrine glands

tyrosine

Amino acid used in the synthesis of hormones like catecholamines and thyroid hormones

water-soluble hormones

hydrophilic hormones that easily dissolve in water

zona fasciculata

intermediate region of the adrenal cortex that produce hormones called glucocorticoids

zona glomerulosa

most superficial region of the adrenal cortex, which produces the hormones collectively referred to as mineralocorticoids

zona reticularis

deepest region of the adrenal cortex, which produces the steroid sex hormones called androgens

18. Blood

ABO blood group

blood-type classification based on the presence or absence of A and B glycoproteins on the erythrocyte membrane surface

agglutination

clustering of cells into masses linked by antibodies

agranular leukocytes

leukocytes with few granules in their cytoplasm; specifically, monocytes, lymphocytes, and NK cells

albumin

most abundant plasma protein, accounting for most of the osmotic pressure of plasma

anemia

deficiency of red blood cells or hemoglobin

antibodies

(also, immunoglobulins or gamma globulins) antigen-specific proteins produced by specialized B lymphocytes that protect the body by binding to foreign objects such as bacteria and viruses

anticoagulant

substance such as heparin that opposes coagulation

antithrombin

anticoagulant that inactivates factor X and opposes the conversion of prothrombin (factor II) into thrombin in the common pathway

B lymphocytes

(also, B cells) lymphocytes that defend the body against specific pathogens and thereby provide specific immunity

basophils

granulocytes that stain with a basic (alkaline) stain and store histamine and heparin

bilirubin

yellowish bile pigment produced when iron is removed from heme and is further broken down into waste products

biliverdin

green bile pigment produced when the non-iron portion of heme is degraded into a waste product; converted to bilirubin in the liver

blood

liquid connective tissue composed of formed elements—erythrocytes, leukocytes, and platelets—and a fluid extracellular matrix called plasma; component of the cardiovascular system

blood colloid osmotic pressure

created by plasma proteins, namely albumin, that do not diffuse readily across the capillary membrane and serves to hold water within the vascular space.

bone marrow biopsy

diagnostic test of a sample of red bone marrow

bone marrow transplant

treatment in which a donor’s healthy bone marrow with its stem cells replaces diseased or damaged bone marrow of a patient

bruise

localized bleeding under the skin due to damaged blood vessels

buffy coat

thin, pale layer of leukocytes and platelets that separates the erythrocytes from the plasma in a sample of centrifuged blood

carbaminohemoglobin

compound of carbon dioxide and hemoglobin, and one of the ways in which carbon dioxide is carried in the blood

Cirrhosis

a chronic disease of the liver marked by degeneration of cells, inflammation, and fibrous thickening of tissue. It is typically a result of alcoholism or hepatitis.

clotting factors

group of 12 identified substances active in coagulation

coagulation

formation of a blood clot; part of the process of hemostasis

colony-stimulating factors (CSFs)

glycoproteins that trigger the proliferation and differentiation of myeloblasts into granular leukocytes (basophils, neutrophils, and eosinophils)

common pathway

final coagulation pathway activated either by the intrinsic or the extrinsic pathway, and ending in the formation of a blood clot

cross matching

blood test for identification of blood type using antibodies and small samples of blood

cytokines

class of proteins that act as autocrine or paracrine signaling molecules; in the cardiovascular system, they stimulate the proliferation of progenitor cells and help to stimulate both nonspecific and specific resistance to disease

defensins

antimicrobial proteins released from neutrophils and macrophages that create openings in the plasma membranes to kill cells

deoxyhemoglobin

molecule of hemoglobin without an oxygen molecule bound to it

diapedesis

(also, emigration) process by which leukocytes squeeze through adjacent cells in a blood vessel wall to enter tissues

embolus

thrombus that has broken free from the blood vessel wall and entered the circulation

emigration

(also, diapedesis) process by which leukocytes squeeze through adjacent cells in a blood vessel wall to enter tissues

Eosinophils

granulocytes that stain with eosin; they release antihistamines and are especially active against parasitic worms

erythroblast

nucleated cell occurring in red marrow as a stage or stages in the development of the red blood cell, or erythrocyte

Erythrocyte

(also, red blood cell) mature myeloid blood cell that is composed mostly of hemoglobin and functions primarily in the transportation of oxygen and carbon dioxide

erythropoietin (EPO)

glycoprotein that triggers the bone marrow to produce RBCs; secreted by the kidney in response to low oxygen levels

extrinsic pathway

initial coagulation pathway that begins with tissue damage and results in the activation of the common pathway

ferritin

protein-containing storage form of iron found in the bone marrow, liver, and spleen

fibrin

insoluble, filamentous protein that forms the structure of a blood clot

fibrinogen

plasma protein produced in the liver and involved in blood clotting

fibrinolysis

gradual degradation of a blood clot

formed elements

cellular components of blood; that is, erythrocytes, leukocytes, and platelets

globin

heme-containing globular protein that is a constituent of hemoglobin

globulins

heterogeneous group of plasma proteins that includes transport proteins, clotting factors, immune proteins, and others

granular leukocytes

leukocytes with abundant granules in their cytoplasm; specifically, neutrophils, eosinophils, and basophils

hematocrit

(also, packed cell volume) volume percentage of erythrocytes in a sample of centrifuged blood

hematopoietic stem cell

type of pluripotent stem cell that gives rise to the formed elements of blood (hemocytoblast)

heme

red, iron-containing pigment to which oxygen binds in hemoglobin

hemocytoblast

hematopoietic stem cell that gives rise to the formed elements of blood

hemoglobin

oxygen-carrying compound in erythrocytes

hemolysis

destruction (lysis) of erythrocytes and the release of their hemoglobin into circulation

hemolytic disease of the newborn (HDN)

(also, erythroblastosis fetalis) disorder causing agglutination and hemolysis in an Rh+ fetus or newborn of an Rh− mother

hemophilia

genetic disorder characterized by inadequate synthesis of clotting factors

hemopoiesis

production of the formed elements of blood

hemopoietic growth factors

chemical signals including erythropoietin, thrombopoietin, colony-stimulating factors, and interleukins that regulate the differentiation and proliferation of particular blood progenitor cells

hemorrhage

excessive bleeding

hemosiderin

protein-containing storage form of iron found in the bone marrow, liver, and spleen

hemostasis

physiological process by which bleeding ceases

heparin

short-acting anticoagulant stored in mast cells and released when tissues are injured, opposes prothrombin

hypoxemia

below-normal level of oxygen saturation of blood (typically <95 percent)

Hypoxic

Consisting of too little oxygen

immunoglobulins

(also, antibodies or gamma globulins) antigen-specific proteins produced by specialized B lymphocytes that protect the body by binding to foreign objects such as bacteria and viruses

interleukins

signaling molecules that may function in hemopoiesis, inflammation, and specific immune responses

intrinsic pathway

initial coagulation pathway that begins with vascular damage or contact with foreign substances, and results in the activation of the common pathway

jaundice

yellowing of the skin or whites of the eyes due to excess bilirubin in the blood

leukemia

cancer involving leukocytes

leukocyte

(also, white blood cell) colorless, nucleated blood cell, the chief function of which is to protect the body from disease

leukocytosis

excessive leukocyte proliferation

leukopenia

below-normal production of leukocytes

lymphocytes

agranular leukocytes of the lymphoid stem cell line, many of which function in specific immunity

lymphoid stem cells

type of hematopoietic stem cells that gives rise to lymphocytes, including various T cells, B cells, and NK cells, all of which function in immunity

lymphoma

form of cancer in which masses of malignant T and/or B lymphocytes collect in lymph nodes, the spleen, the liver, and other tissues

lysozyme

digestive enzyme with bactericidal properties

macrophage

phagocytic cell of the myeloid lineage; a matured monocyte

megakaryocyte

bone marrow cell that produces platelets

memory cell

type of B or T lymphocyte that forms after exposure to a pathogen

monocytes

agranular leukocytes of the myeloid stem cell line that circulate in the bloodstream; tissue monocytes are macrophages

myeloid stem cells

type of hematopoietic stem cell that gives rise to some formed elements, including erythrocytes, megakaryocytes that produce platelets, and a myeloblast lineage that gives rise to monocytes and three forms of granular leukocytes (neutrophils, eosinophils, and basophils)

natural killer (NK) cells

cytotoxic lymphocytes capable of recognizing cells that do not express “self” proteins on their plasma membrane or that contain foreign or abnormal markers; provide generalized, nonspecific immunity

neutrophils

granulocytes that stain with a neutral dye and are the most numerous of the leukocytes; especially active against bacteria

oxyhemoglobin

molecule of hemoglobin to which oxygen is bound

packed cell volume (PCV)

(also, hematocrit) volume percentage of erythrocytes present in a sample of centrifuged blood

plasma

in blood, the liquid extracellular matrix composed mostly of water that circulates the formed elements and dissolved materials throughout the cardiovascular system

plasmin

blood protein active in fibrinolysis

platelet plug

accumulation and adhesion of platelets at the site of blood vessel injury

platelets

(also, thrombocytes) one of the formed elements of blood that consists of cell fragments broken off from megakaryocytes

pluripotent stem cell

stem cell that derives from totipotent stem cells and is capable of differentiating into many, but not all, cell types

polycythemia

elevated level of hemoglobin, whether adaptive or pathological

polymorphonuclear

having a lobed nucleus, as seen in some leukocytes

positive chemotaxis

process in which a cell is attracted to move in the direction of chemical stimuli

red blood cells (RBCs)

(also, erythrocytes) one of the formed elements of blood that transports oxygen

reticulocyte

immature erythrocyte that may still contain fragments of organelles

Rh blood group

blood-type classification based on the presence or absence of the antigen Rh on the erythrocyte membrane surface

Rouleaux

Collection of red blood cells resembling stacked plates

serum

blood plasma that does not contain clotting factors

sickle cell anemia

(also, sickle cell disease) inherited blood disorder in which hemoglobin molecules are malformed, leading to the breakdown of RBCs that take on a characteristic sickle shape

Stercobilins

Stercobilin is a tetrapyrrolic bile pigment and is one end-product of heme catabolism.

T lymphocytes

(also, T cells) lymphocytes that provide cellular-level immunity by physically attacking foreign or diseased cells

thalassemia

inherited blood disorder in which maturation of RBCs does not proceed normally, leading to abnormal formation of hemoglobin and the destruction of RBCs

thrombin

enzyme essential for the final steps in formation of a fibrin clot

thrombocytes

platelets, one of the formed elements of blood that consists of cell fragments broken off from megakaryocytes

thrombocytopenia

condition in which there are too few platelets, resulting in abnormal bleeding (hemophilia)

thrombocytosis

condition in which there are too many platelets, resulting in abnormal clotting (thrombosis)

thrombopoietin

hormone secreted by the liver and kidneys that prompts the development of megakaryocytes into thrombocytes (platelets)

thrombosis

excessive clot formation

thrombus

aggregation of fibrin, platelets, and erythrocytes in an intact artery or vein

tissue factor

protein thromboplastin, which initiates the extrinsic pathway when released in response to tissue damage

totipotent stem cell

embryonic stem cell that is capable of differentiating into any and all cells of the body; enabling the full development of an organism

transferrin

plasma protein that binds reversibly to iron and distributes it throughout the body

universal donor

individual with type O− blood

universal recipient

individual with type AB+ blood

Urobilins

is the chemical primarily responsible for the yellow color of urine. It is a linear tetrapyrrole compound that, along with the related colorless compound urobilinogen, are degradation products of the cyclic tetrapyrrole heme.

vascular spasm

initial step in hemostasis, in which the smooth muscle in the walls of the ruptured or damaged blood vessel contracts

white blood cells (WBCs)

(also, leukocytes) one of the formed elements of blood that provides defense against disease agents and foreign materials

whole blood

blood drawn directly from the body from which none of the components, such as plasma or platelets, has been removed

19. The heart

afterload

force the ventricles must develop to effectively pump blood against the resistance in the vessels

anastomosis

(plural = anastomoses) area where vessels unite to allow blood to circulate even if there may be partial blockage in another branch

angioplasty

a procedure in which a blockage is mechanically widened with a balloon

anterior interventricular artery

(also, left anterior descending artery or LAD) major branch of the left coronary artery that follows the anterior interventricular sulcus

anterior interventricular sulcus

sulcus located between the left and right ventricles on the anterior surface of the heart

aorta

largest artery in the body, originating from the left ventricle and descending to the abdominal region where it bifurcates into the common iliac arteries at the level of the fourth lumbar vertebra; arteries originating from the aorta distribute blood to virtually all tissues of the body

aortic arch

descends toward the inferior portions of the body and ends at the level of the intervertebral disk between the fourth and fifth thoracic vertebrae

aortic stenosis

most common condition resulting from stenosis and it can be heard during auscultation as a high-pitched hum due to the turbulence created as the blood is forced through the narrowed valve

aortic valve

(also, aortic semilunar valve) valve located at the base of the aorta

arrhythmias

unusual rhythm of heartbeats where the heart is beating too slowly, too quickly, or irregularly

artery

blood vessel that conducts blood away from the heart; may be a conducting or distributing vessel

ascending aorta

initial portion of the aorta, rising from the left ventricle for a distance of approximately 5 cm

athlete’s heart

A type of benign hypertrophy that involves hypertrophy of primarily the myocardium of the left ventricular and not the interventricular septum

atrial fibrillation

most common arrhythmia that starts in the atria

atrial reflex

(also, called Bainbridge reflex) autonomic reflex that responds to stretch receptors in the atria that send impulses to the cardioaccelerator area to increase HR when venous flow into the atria increases

atrioventricular (AV) node

clump of myocardial cells located in the inferior portion of the right atrium within the atrioventricular septum; receives the impulse from the SA node, pauses, and then transmits it into specialized conducting cells within the interventricular septum

atrioventricular bundle

(also, bundle of His) group of specialized myocardial conductile cells that transmit the impulse from the AV node through the interventricular septum; form the left and right atrioventricular bundle branches

atrioventricular bundle branches

(also, left or right bundle branches) specialized myocardial conductile cells that arise from the bifurcation of the atrioventricular bundle and pass through the interventricular septum; lead to the Purkinje fibers and also to the right papillary muscle via the moderator band

atrioventricular septum

cardiac septum located between the atria and ventricles; atrioventricular valves are located here

atrial systole

atrial contraction phase follows atrial depolarization which is represented by the P wave of the ECG

atrioventricular valves

one-way valves located between the atria and ventricles; the valve on the right is called the tricuspid valve, and the one on the left is the mitral or bicuspid valve

atrium

(plural = atria) upper or receiving chamber of the heart that pumps blood into the lower chambers just prior to their contraction; the right atrium receives blood from the systemic circuit that flows into the right ventricle; the left atrium receives blood from the pulmonary circuit that flows into the left ventricle

auricle

extension of an atrium visible on the superior surface of the heart

autonomic reflexes

regulate the ability of the autonomic nervous system to influence heart rate

autonomic tone

contractile state during resting cardiac activity produced by mild sympathetic and parasympathetic stimulation

autorhythmicity

ability of cardiac muscle to initiate its own electrical impulse that triggers the mechanical contraction that pumps blood at a fixed pace without nervous or endocrine control

Bainbridge reflex

(also, called atrial reflex) autonomic reflex that responds to stretch receptors in the atria that send impulses to the cardioaccelerator area to increase HR when venous flow into the atria increases

baroreceptor reflex

autonomic reflex in which the cardiac centers monitor signals from the baroreceptor stretch receptors and regulate heart function based on blood flow

bicuspid valve

(also, mitral valve or left atrioventricular valve) valve located between the left atrium and ventricle; consists of two flaps of tissue

bradycardia

condition of having a heart rate (HR) below 50 beats per minute (bpm)

bundle of His

(also, atrioventricular bundle) group of specialized myocardial conductile cells that transmit the impulse from the AV node through the interventricular septum; form the left and right atrioventricular bundle branches

capillary

smallest of blood vessels where physical exchange occurs between the blood and tissue cells surrounded by interstitial fluid

cardiac center

area within the medulla oblongata that regulates heart rate through the nervous and endocrine systems

cardiac cycle

period of time between the onset of atrial contraction (atrial systole) and ventricular relaxation (ventricular diastole)

cardiac notch

depression in the medial surface of the inferior lobe of the left lung where the apex of the heart is located

cardiac output (CO)

amount of blood pumped by each ventricle during one minute; equals HR multiplied by SV

cardiac reserve

difference between maximum and resting CO

cardiac tamponade

condition where the heart is not able to pump blood anymore

cardioacceleratory center

sends sympathetic signals to increase heart rate and force of contraction

cardioinhibitory center

sends parasympathetic signals via the vagus nerves

chordae tendineae

string-like extensions of tough connective tissue that extend from the flaps of the atrioventricular valves to the papillary muscles

chronotropic agents

factors that can change heart rate

circumflex artery

branch of the left coronary artery that follows coronary sulcus

conducting (nodal) cells

cells that initiate and propagate the action potential (the electrical impulse) that travels throughout the heart

contractile cells

these cells conduct impulses and undergo contractions that pump blood through the body

coronary arteries

branches of the ascending aorta that supply blood to the heart; the left coronary artery feeds the left side of the heart, the left atrium and ventricle, and the interventricular septum; the right coronary artery feeds the right atrium, portions of both ventricles, and the heart conduction system

coronary artery disease

also known as coronary heart disease, is characterized by the buildup of plaque (atherosclerosis), which is a fatty material including cholesterol, within the coronary arteries

coronary circulation

circulation of blood in the blood vessels that supply the heart muscle

coronary sinus

large, thin-walled vein on the posterior surface of the heart that lies within the atrioventricular sulcus and drains the heart myocardium directly into the right atrium

coronary sulcus

sulcus that marks the boundary between the atria and ventricles

coronary veins

vessels that drain the heart and generally parallel the large surface arteries

defibrillation

treatment which uses special paddles to apply an electric charge to the heart

depolarization

change in a cell membrane potential from rest toward zero. It results from the movement of sodium ions entering the cells

descending aorta

portion of the aorta that continues downward past the end of the aortic arch; subdivided into the thoracic aorta and the abdominal aorta

diastole

period of time when the heart muscle is relaxed and the chambers fill with blood

dicrotic notch

It is seen in the ECG and produced by the tendency for blood to flow back into the atria from the major arteries as ventricular pressure drops, following ventricular repolarization, when the ventricles begin to relax (ventricular diastole), and pressure within the ventricles drops.

electrocardiogram (ECG)

surface recording of the electrical activity of the heart that can be used for diagnosis of irregular heart function; also abbreviated as EKG

end diastolic volume (EDV)

(also, preload) the amount of blood in the ventricles at the end of atrial systole just prior to ventricular contraction

end systolic volume (ESV)

amount of blood remaining in each ventricle following systole

endocardium

innermost layer of the heart lining the heart chambers and heart valves; composed of endothelium reinforced with a thin layer of connective tissue that binds to the myocardium

endothelium

layer of smooth, simple squamous epithelium that lines the endocardium and blood vessels

epicardium

innermost layer of the serous pericardium and the outermost layer of the heart wall

fibrous pericardium

dense irregular connective tissue that encloses and protects the heart

fibrous skeleton

anchors the heart valves and works as an electric insulator

foramen ovale

opening in the fetal heart that allows blood to flow directly from the right atrium to the left atrium, bypassing the fetal pulmonary circuit

fossa ovalis

oval-shaped depression in the interatrial septum that marks the former location of the foramen ovale

Frank-Starling Law

relationship between ventricular stretch and contraction in which the force of heart contraction is directly proportional to the initial length of the muscle fiber

great cardiac vein

vessel that follows the interventricular sulcus on the anterior surface of the heart and flows along the coronary sulcus into the coronary sinus on the posterior surface; parallels the anterior interventricular artery and drains the areas supplied by this vessel

gap junctions

they allow the passage of ions between the cells to help to synchronize the heart contraction

heart block

interruption in the normal conduction pathway

heart rate (HR)

number of times the heart contracts (beats) per minute

heart sounds

sounds heard via auscultation with a stethoscope of the closing of the atrioventricular valves (“lub”) and semilunar valves (“dub”)

heart murmur

sound coming from the heart that is caused by the turbulent flow of blood

hypertrophic cardiomyopathy

pathological enlargement of the heart, generally for no known reason

inferior vena cava

large systemic vein that returns blood to the heart from the inferior portion of the body

inotropic agents

factors that change stroke volume by affecting contractility

interatrial septum

cardiac septum located between the two atria; contains the fossa ovalis after birth

intercalated disc

physical junction between adjacent cardiac muscle cells; consisting of desmosomes, specialized linking proteoglycans, and gap junctions that allow passage of ions between the two cells

internodal pathways

specialized conductile cells within the atria that transmit the impulse from the SA node throughout the myocardial cells of the atrium and to the AV node

interventricular septum

cardiac septum located between the two ventricles

interventricular sulcus

groove between the ventricles

ischemia

a reduction in blood flow that results in hypoxia (insufficient delivery of oxygen to the cells and tissues of the body)

isovolumic contraction

(also, isovolumetric contraction) initial phase of ventricular contraction in which tension and pressure in the ventricle increase, but no blood is pumped or ejected from the heart

isovolumic ventricular relaxation phase

initial phase of the ventricular diastole when pressure in the ventricles drops below pressure in the two major arteries, the pulmonary trunk, and the aorta, and blood attempts to flow back into the ventricles, producing the dicrotic notch of the ECG and closing the two semilunar valves

left atrioventricular valve

(also, mitral valve or bicuspid valve) valve located between the left atrium and ventricle; consists of two flaps of tissue

left auricle

flaplike extension on the surface of the left atrium

mediastinum

area within the thoracic cavity that contains the lungs and the heart

middle cardiac vein

vessel that parallels and drains the areas supplied by the posterior interventricular artery; drains into the great cardiac vein

mitral valve

(also, left atrioventricular valve or bicuspid valve) valve located between the left atrium and ventricle; consists of two flaps of tissue

mitral valve prolapse

one of the cusps of the mitral valve is forced backward by the force of the blood

moderator band

band of myocardium covered by endocardium that arises from the inferior portion of the interventricular septum in the right ventricle and crosses to the anterior papillary muscle; contains conductile fibers that carry electrical signals followed by contraction of the heart

murmur

unusual heart sound detected by auscultation; typically related to septal or valve defects

conducting cells

specialized cells that transmit electrical impulses throughout the heart and trigger contraction by the myocardial contractile cells

contractile cells

bulk of the cardiac muscle cells in the atria and ventricles that conduct impulses and contract to propel blood

myocardium

thickest layer of the heart composed of cardiac muscle cells built upon a framework of primarily collagenous fibers and blood vessels that supply it and the nervous fibers that help to regulate it

myocardial infarction

commonly known as a heart attack, results from a complete blockage of a coronary artery, or more likely several coronary arteries, resulting in the death of the cardiac muscle cells (necrosis)

negative inotropic factors

factors that negatively impact or lower heart contractility

P wave

component of the electrocardiogram that represents the depolarization of the atria

pacemaker

cluster of specialized myocardial cells known as the SA node that initiates the sinus rhythm

papillary muscle

extension of the myocardium in the ventricles to which the chordae tendineae attach

pectinate muscles

muscular ridges seen on the anterior surface of the right atrium

pericardial cavity

cavity surrounding the heart filled with a lubricating serous fluid that reduces friction as the heart contracts

pericardial sac

(also, pericardium) membrane that separates the heart from other mediastinal structures; consists of two distinct, fused sublayers: the fibrous pericardium and the parietal pericardium

pericarditis

inflammation of the pericardium

pericardium

(also, pericardial sac) membrane that separates the heart from other mediastinal structures; consists of two distinct, fused sublayers: the fibrous pericardium and the parietal pericardium

positive inotropic factors

factors that positively impact or increase heart contractility

posterior interventricular artery

(also, posterior descending artery) branch of the right coronary artery that runs along the posterior portion of the interventricular sulcus toward the apex of the heart and gives rise to branches that supply the interventricular septum and portions of both ventricles

posterior interventricular sulcus

sulcus located between the left and right ventricles on the posterior surface of the heart

preload

(also, end diastolic volume) amount of blood in the ventricles at the end of atrial systole just prior to ventricular contraction

pulmonary arteries

left and right branches of the pulmonary trunk that carry deoxygenated blood from the heart to each of the lungs

pulmonary capillaries

capillaries surrounding the alveoli of the lungs where gas exchange occurs: carbon dioxide exits the blood and oxygen enters

pulmonary circulation

movement of blood from the right side of the heart to the lungs, and back to the left side of the heart

pulmonary circuit

blood flow to and from the lungs

pulmonary trunk

large arterial vessel that carries blood ejected from the right ventricle; divides into the left and right pulmonary arteries

pulmonary valve

(also, pulmonary semilunar valve, the pulmonic valve, or the right semilunar valve) valve at the base of the pulmonary trunk that prevents backflow of blood into the right ventricle; consists of three flaps

pulmonary veins

veins that carry highly oxygenated blood into the left atrium, which pumps the blood into the left ventricle, which in turn pumps oxygenated blood into the aorta and to the many branches of the systemic circuit

Purkinje fibers

specialized myocardial conduction fibers that arise from the bundle branches and spread the impulse to the myocardial contraction fibers of the ventricles

QRS complex

component of the electrocardiogram that represents the depolarization of the ventricles and includes, as a component, the repolarization of the atria

repolarization

it results from the outflux of positively charged K+

right atrioventricular valve

(also, tricuspid valve) valve located between the right atrium and ventricle; consists of three flaps of tissue

right auricle

flaplike extension on the surface of the right atrium

right marginal artery

a branch from the right coronary artery that supplies the lateral wall of the right ventricle

semilunar valves

valves located at the base of the pulmonary trunk and at the base of the aorta

septum

(plural = septa) walls or partitions that divide the heart into chambers

serous fluid

oily fluid helps diminish friction as the heart contracts and expands

sinoatrial (SA) node

known as the pacemaker, a specialized clump of myocardial conducting cells located in the superior portion of the right atrium that has the highest inherent rate of depolarization that then spreads throughout the heart

sinus rhythm

normal contractile pattern of the heart

small cardiac vein

parallels the right coronary artery and drains blood from the posterior surfaces of the right atrium and ventricle; drains into the coronary sinus, middle cardiac vein, or right atrium

spontaneous depolarization

(also, prepotential depolarization) the mechanism that accounts for the autorhythmic property of cardiac muscle; the membrane potential increases as sodium ions diffuse through the always-open sodium ion channels and causes the electrical potential to rise

stroke volume (SV)

amount of blood pumped by each ventricle per contraction; also, the difference between EDV and ESV

sulcus

(plural = sulci) fat-filled groove visible on the surface of the heart; coronary vessels are also located in these areas

superior vena cava

large systemic vein that returns blood to the heart from the superior portion of the body

systemic circulation

movement of blood from the left side of the heart to the systemic cells of the body and then back to the right side of the heart

systemic circuit

blood flow to and from virtually all of the tissues of the body

systole

period of time when the heart muscle is contracting

T wave

component of the electrocardiogram that represents the repolarization of the ventricles

trabeculae carneae

ridges of muscle covered by endocardium located in the ventricles

tricuspid valve

term used most often in clinical settings for the right atrioventricular valve

valve

in the cardiovascular system, a specialized structure located within the heart or vessels that ensures one-way flow of blood

vein

blood vessel that conducts blood toward the heart

ventricle

one of the primary pumping chambers of the heart located in the lower portion of the heart; the left ventricle is the major pumping chamber on the lower left side of the heart that ejects blood into the systemic circuit via the aorta and receives blood from the left atrium; the right ventricle is the major pumping chamber on the lower right side of the heart that ejects blood into the pulmonary circuit via the pulmonary trunk and receives blood from the right atrium

ventricular ejection phase

second phase of ventricular systole during which blood is pumped from the ventricle

ventricular fibrillation

arrhythmia that starts in the ventricle

ventricular relaxation

also known as ventricular diastole, follows the repolarization of the ventricles and is represented by the T wave of the ECG

ventricular systole

follows the depolarization of the ventricles represented by the QRS complex in the ECG

ventricular tachycardia

heart rate above 100 bpm

20. Vasculature

abdominal aorta

portion of the aorta inferior to the aortic hiatus and superior to the common iliac

arteries

adrenal artery

branch of the abdominal aorta; supplies blood to the adrenal (suprarenal) glands

adrenal vein

drains the adrenal or suprarenal glands that are immediately superior to the kidneys; the right adrenal vein enters the inferior vena cava directly and the left adrenal vein enters the left renal vein

anaphylactic shock

type of shock that follows a severe allergic reaction and results from massive vasodilation

angioblasts

stem cells that give rise to blood vessels

angiogenesis

development of new blood vessels from existing vessels

anterior cerebral artery

arises from the internal carotid artery; supplies the frontal lobe of the cerebrum

anterior communicating artery

anastomosis of the right and left internal carotid arteries; supplies blood to the brain

anterior tibial artery

branches from the popliteal artery; supplies blood to the anterior tibial region; becomes the dorsalis pedis artery

anterior tibial vein

forms from the dorsal venous arch; drains the area near the tibialis anterior muscle and leads to the popliteal vein

aorta

largest artery in the body, originating from the left ventricle and descending to the abdominal region where it bifurcates into the common iliac arteries at the level of the fourth lumbar vertebra; arteries originating from the aorta distribute blood to virtually all tissues of the body

aortic arch

arc that connects the ascending aorta to the descending aorta; ends at the intervertebral disk between the fourth and fifth thoracic vertebrae

aortic hiatus

opening in the diaphragm that allows passage of the thoracic aorta into the abdominal region where it becomes the abdominal aorta

aortic sinuses

small pockets in the ascending aorta near the aortic valve that are the locations of the baroreceptors (stretch receptors) and chemoreceptors that trigger a reflex that aids in the regulation of vascular homeostasis

arterial circle

(also, circle of Willis) anastomosis located at the base of the brain that ensures continual blood supply; formed from branches of the internal carotid and vertebral arteries; supplies blood to the brain

arteriole

(also, resistance vessel) very small artery that leads to a capillary

arteriovenous anastomosis

short vessel connecting an arteriole directly to a venule and bypassing the capillary beds

artery

blood vessel that conducts blood away from the heart; may be a conducting or distributing vessel

ascending aorta

initial portion of the aorta, rising from the left ventricle for a distance of approximately 5 cm

atrial reflex

mechanism for maintaining vascular homeostasis involving atrial baroreceptors: if blood is returning to the right atrium more rapidly than it is being ejected from the left ventricle, the atrial receptors will stimulate the cardiovascular centers to increase sympathetic firing and increase cardiac output until the situation is reversed; the opposite is also true

axillary artery

continuation of the subclavian artery as it penetrates the body wall and enters the axillary region; supplies blood to the region near the head of the humerus (humeral circumflex arteries); the majority of the vessel continues into the brachium and becomes the brachial artery

axillary vein

major vein in the axillary region; drains the upper limb and becomes the subclavian vein

azygos vein

originates in the lumbar region and passes through the diaphragm into the thoracic cavity on the right side of the vertebral column; drains blood from the intercostal veins, esophageal veins, bronchial veins, and other veins draining the mediastinal region; leads to the superior vena cava

basilar artery

formed from the fusion of the two vertebral arteries; sends branches to the cerebellum, brain stem, and the posterior cerebral arteries; the main blood supply to the brain stem

basilic vein

superficial vein of the arm that arises from the palmar venous arches, intersects with the median cubital vein, parallels the ulnar vein, and continues into the upper arm; along with the brachial vein, it leads to the axillary vein

blood colloidal osmotic pressure (BCOP)

pressure exerted by colloids suspended in blood within a vessel; a primary determinant is the presence of plasma proteins

blood flow

movement of blood through a vessel, tissue, or organ that is usually expressed in terms of volume per unit of time

blood hydrostatic pressure (BHP)

force blood exerts against the walls of a blood vessel or heart chamber

blood pressure

force exerted by the blood against the wall of a vessel or heart chamber; can be described with the more generic term hydrostatic pressure

brachial artery

continuation of the axillary artery in the brachium; supplies blood to much of the brachial region; gives off several smaller branches that provide blood to the posterior surface of the arm in the region of the elbow; bifurcates into the radial and ulnar arteries at the coronoid fossa

brachial vein

deeper vein of the arm that forms from the radial and ulnar veins in the lower arm; leads to the axillary vein

brachiocephalic artery

(also, brachiocephalic trunk) single vessel located on the right side of the body; the first vessel branching from the aortic arch; gives rise to the right subclavian artery and the right common carotid artery; supplies blood to the head, neck, upper limb, and wall of the thoracic region

brachiocephalic vein

one of a pair of veins that form from a fusion of the external and internal jugular veins and the subclavian vein; subclavian, external and internal jugulars, vertebral, and internal thoracic veins lead to it; drains the upper thoracic region and flows into the superior vena cava

bronchial artery

systemic branch from the aorta that provides oxygenated blood to the lungs in addition to the pulmonary circuit

bronchial vein

drains the systemic circulation from the lungs and leads to the azygos vein

capacitance

ability of a vein to distend and store blood

capacitance vessels

veins

capillary

smallest of blood vessels where physical exchange occurs between the blood and tissue cells surrounded by interstitial fluid

capillary bed

network of 10–100 capillaries connecting arterioles to venules

capillary hydrostatic pressure (CHP)

force blood exerts against a capillary

cardiogenic shock

type of shock that results from the inability of the heart to maintain cardiac output

carotid sinuses

small pockets near the base of the internal carotid arteries that are the locations of the baroreceptors and chemoreceptors that trigger a reflex that aids in the regulation of vascular homeostasis

cavernous sinus

enlarged vein that receives blood from most of the other cerebral veins and the eye socket, and leads to the petrosal sinus

celiac trunk

(also, celiac artery) major branch of the abdominal aorta; gives rise to the left gastric artery, the splenic artery, and the common hepatic artery that forms the hepatic artery to the liver, the right gastric artery to the stomach, and the cystic artery to the gallbladder

cephalic vein

superficial vessel in the upper arm; leads to the axillary vein

cerebrovascular accident (CVA)

blockage of blood flow to the brain; also called a stroke

circle of Willis

(also, arterial circle) anastomosis located at the base of the brain that ensures continual blood supply; formed from branches of the internal carotid and vertebral arteries; supplies blood to the brain

circulatory shock

also simply called shock; a life-threatening medical condition in which the circulatory system is unable to supply enough blood flow to provide adequate oxygen and other nutrients to the tissues to maintain cellular metabolism

common carotid artery

right common carotid artery arises from the brachiocephalic artery, and the left common carotid arises from the aortic arch; gives rise to the external and internal carotid arteries; supplies the respective sides of the head and neck

common hepatic artery

branch of the celiac trunk that forms the hepatic artery, the right gastric artery, and the cystic artery

common iliac artery

branch of the aorta that leads to the internal and external iliac arteries

common iliac vein

one of a pair of veins that flows into the inferior vena cava at the level of L5; the left common iliac vein drains the sacral region; divides into external and internal iliac veins near the inferior portion of the sacroiliac joint

compliance

degree to which a blood vessel can stretch as opposed to being rigid

continuous capillary

most common type of capillary, found in virtually all tissues except epithelia and cartilage; contains very small gaps in the endothelial lining that permit exchange

cystic artery

branch of the common hepatic artery; supplies blood to the gallbladder

deep femoral artery

branch of the femoral artery; gives rise to the lateral circumflex arteries

deep femoral vein

drains blood from the deeper portions of the thigh and leads to the femoral vein

descending aorta

portion of the aorta that continues downward past the end of the aortic arch; subdivided into the thoracic aorta and the abdominal aorta

diastolic pressure

lower number recorded when measuring arterial blood pressure; represents the minimal value corresponding to the pressure that remains during ventricular relaxation

digital arteries

formed from the superficial and deep palmar arches; supply blood to the digits

digital veins

drain the digits and feed into the palmar arches of the hand and dorsal venous arch of the foot

dorsal arch

(also, arcuate arch) formed from the anastomosis of the dorsalis pedis artery and medial and plantar arteries; branches supply the distal portions of the foot and digits

dorsal venous arch

drains blood from digital veins and vessels on the superior surface of the foot

dorsalis pedis artery

forms from the anterior tibial artery; branches repeatedly to supply blood to the tarsal and dorsal regions of the foot

elastic artery

(also, conducting artery) artery with abundant elastic fibers located closer to the heart, which maintains the pressure gradient and conducts blood to smaller branches

esophageal artery

branch of the thoracic aorta; supplies blood to the esophagus

esophageal vein

drains the inferior portions of the esophagus and leads to the azygos vein

external carotid artery

arises from the common carotid artery; supplies blood to numerous structures within the face, lower jaw, neck, esophagus, and larynx

external elastic membrane

membrane composed of elastic fibers that separates the tunica media from the tunica externa; seen in larger arteries

external iliac artery

branch of the common iliac artery that leaves the body cavity and becomes a femoral artery; supplies blood to the lower limbs

external iliac vein

formed when the femoral vein passes into the body cavity; drains the legs and leads to the common iliac vein

external jugular vein

one of a pair of major veins located in the superficial neck region that drains blood from the more superficial portions of the head, scalp, and cranial regions, and leads to the subclavian vein

femoral artery

continuation of the external iliac artery after it passes through the body cavity; divides into several smaller branches, the lateral deep femoral artery, and the genicular artery; becomes the popliteal artery as it passes posterior to the knee

femoral circumflex vein

forms a loop around the femur just inferior to the trochanters; drains blood from the areas around the head and neck of the femur; leads to the femoral vein

femoral vein

drains the upper leg; receives blood from the great saphenous vein, the deep femoral vein, and the femoral circumflex vein; becomes the external iliac vein when it crosses the body wall

fenestrated capillary

type of capillary with pores or fenestrations in the endothelium that allow for rapid passage of certain small materials

fibular vein

drains the muscles and integument near the fibula and leads to the popliteal vein

filtration

in the cardiovascular system, the movement of material from a capillary into the interstitial fluid, moving from an area of higher pressure to lower pressure

genicular artery

branch of the femoral artery; supplies blood to the region of the knee

gonadal artery

branch of the abdominal aorta; supplies blood to the gonads or reproductive organs; also described as ovarian arteries or testicular arteries, depending upon the sex of the individual

gonadal vein

generic term for a vein draining a reproductive organ; may be either an ovarian vein or a testicular vein, depending on the sex of the individual

great cerebral vein

receives most of the smaller vessels from the inferior cerebral veins and leads to the straight sinus

great saphenous vein

prominent surface vessel located on the medial surface of the leg and thigh; drains the superficial portions of these areas and leads to the femoral vein

hemangioblasts

embryonic stem cells that appear in the mesoderm and give rise to both angioblasts and pluripotent stem cells

hemiazygos vein

smaller vein complementary to the azygos vein; drains the esophageal veins from the esophagus and the left intercostal veins, and leads to the brachiocephalic vein via the superior intercostal vein

hepatic artery proper

branch of the common hepatic artery; supplies systemic blood to the liver

hepatic portal system

specialized circulatory pathway that carries blood from digestive organs to the liver for processing before being sent to the systemic circulation

hepatic vein

drains systemic blood from the liver and flows into the inferior vena cava

hypertension

chronic and persistent blood pressure measurements of 140/90 mm Hg or above

hypervolemia

abnormally high levels of fluid and blood within the body

hypovolemia

abnormally low levels of fluid and blood within the body

hypovolemic shock

type of circulatory shock caused by excessive loss of blood volume due to hemorrhage or possibly dehydration

hypoxia

lack of oxygen supply to the tissues

inferior mesenteric artery

branch of the abdominal aorta; supplies blood to the distal segment of the large intestine and rectum

inferior phrenic artery

branch of the abdominal aorta; supplies blood to the inferior surface of the diaphragm

inferior vena cava

large systemic vein that drains blood from areas largely inferior to the diaphragm; empties into the right atrium

intercostal artery

branch of the thoracic aorta; supplies blood to the muscles of the thoracic cavity and vertebral column

intercostal vein

drains the muscles of the thoracic wall and leads to the azygos vein

internal carotid artery

arises from the common carotid artery and begins with the carotid sinus; goes through the carotid canal of the temporal bone to the base of the brain; combines with branches of the vertebral artery forming the arterial circle; supplies blood to the brain

internal elastic membrane

membrane composed of elastic fibers that separates the tunica intima from the tunica media; seen in larger arteries

internal iliac artery

branch from the common iliac arteries; supplies blood to the urinary bladder, walls of the pelvis, external genitalia, and the medial portion of the femoral region; in females, also provide blood to the uterus and vagina

internal iliac vein

drains the pelvic organs and integument; formed from several smaller veins in the region; leads to the common iliac vein

internal jugular vein

one of a pair of major veins located in the neck region that passes through the jugular foramen and canal, flows parallel to the common carotid artery that is more or less its counterpart; primarily drains blood from the brain, receives the superficial facial vein, and empties into the subclavian vein

internal thoracic artery

(also, mammary artery) arises from the subclavian artery; supplies blood to the thymus, pericardium of the heart, and the anterior chest wall

internal thoracic vein

(also, internal mammary vein) drains the anterior surface of the chest wall and leads to the brachiocephalic vein

interstitial fluid colloidal osmotic pressure (IFCOP)

pressure exerted by the colloids within the interstitial fluid

interstitial fluid hydrostatic pressure (IFHP)

force exerted by the fluid in the tissue spaces

ischemia

insufficient blood flow to the tissues

Korotkoff sounds

noises created by turbulent blood flow through the vessels

lateral circumflex artery

branch of the deep femoral artery; supplies blood to the deep muscles of the thigh and the ventral and lateral regions of the integument

lateral plantar artery

arises from the bifurcation of the posterior tibial arteries; supplies blood to the lateral plantar surfaces of the foot

left gastric artery

branch of the celiac trunk; supplies blood to the stomach

lumbar arteries

branches of the abdominal aorta; supply blood to the lumbar region, the abdominal wall, and spinal cord

lumbar veins

drain the lumbar portion of the abdominal wall and spinal cord; the superior lumbar veins drain into the azygos vein on the right or the hemiazygos vein on the left; blood from these vessels is returned to the superior vena cava rather than the inferior vena cava

lumen

interior of a tubular structure such as a blood vessel or a portion of the alimentary canal through which blood, chyme, or other substances travel

maxillary vein

drains blood from the maxillary region and leads to the external jugular vein

mean arterial pressure (MAP)

average driving force of blood to the tissues; approximated by taking diastolic pressure and adding 1/3 of pulse pressure

medial plantar artery

arises from the bifurcation of the posterior tibial arteries; supplies blood to the medial plantar surfaces of the foot

median antebrachial vein

vein that parallels the ulnar vein but is more medial in location; intertwines with the palmar venous arches

median cubital vein

superficial vessel located in the antecubital region that links the cephalic vein to the basilic vein in the form of a v; a frequent site for a blood draw

median sacral artery

continuation of the aorta into the sacrum

mediastinal artery

branch of the thoracic aorta; supplies blood to the mediastinum

metarteriole

short vessel arising from a terminal arteriole that branches to supply a capillary bed

microcirculation

blood flow through the capillaries

middle cerebral artery

another branch of the internal carotid artery; supplies blood to the temporal and parietal lobes of the cerebrum

middle sacral vein

drains the sacral region and leads to the left common iliac vein

muscular artery

(also, distributing artery) artery with abundant smooth muscle in the tunica media that branches to distribute blood to the arteriole network

myogenic response

constriction or dilation in the walls of arterioles in response to pressures related to blood flow; reduces high blood flow or increases low blood flow to help maintain consistent flow to the capillary network

nervi vasorum

small nerve fibers found in arteries and veins that trigger contraction of the smooth muscle in their walls

net filtration pressure (NFP)

force driving fluid out of the capillary and into the tissue spaces; equal to the difference of the capillary hydrostatic pressure and the blood colloidal osmotic pressure

neurogenic shock

type of shock that occurs with cranial or high spinal injuries that damage the cardiovascular centers in the medulla oblongata or the nervous fibers originating from this region

obstructive shock

type of shock that occurs when a significant portion of the vascular system is blocked

occipital sinus

enlarged vein that drains the occipital region near the falx cerebelli and flows into the left and right transverse sinuses, and also into the vertebral veins

ophthalmic artery

branch of the internal carotid artery; supplies blood to the eyes

ovarian artery

branch of the abdominal aorta; supplies blood to the ovary, uterine (Fallopian) tube, and uterus

ovarian vein

drains the ovary; the right ovarian vein leads to the inferior vena cava and the left ovarian vein leads to the left renal vein

palmar arches

superficial and deep arches formed from anastomosis of the radial and ulnar arteries; supply blood to the hand and digital arteries

palmar venous arches

drain the hand and digits, and feed into the radial and ulnar veins

parietal branches

(also, somatic branches) group of arterial branches of the thoracic aorta; includes those that supply blood to the thoracic cavity, vertebral column, and the superior surface of the diaphragm

perfusion

distribution of blood into the capillaries so the tissues can be supplied

pericardial artery

branch of the thoracic aorta; supplies blood to the pericardium

petrosal sinus

enlarged vein that receives blood from the cavernous sinus and flows into the internal

jugular vein

phrenic vein

drains the diaphragm; the right phrenic vein flows into the inferior vena cava and the left phrenic vein leads to the left renal vein

plantar arch

formed from the anastomosis of the dorsalis pedis artery and medial and plantar arteries; branches supply the distal portions of the foot and digits

plantar veins

drain the foot and lead to the plantar venous arch

plantar venous arch

formed from the plantar veins; leads to the anterior and posterior tibial veins through anastomoses

popliteal artery

continuation of the femoral artery posterior to the knee; branches into the anterior and posterior tibial arteries

popliteal vein

continuation of the femoral vein behind the knee; drains the region behind the knee and forms from the fusion of the fibular and anterior and posterior tibial veins

posterior cerebral artery

branch of the basilar artery that forms a portion of the posterior segment of the arterial circle; supplies blood to the posterior portion of the cerebrum and brain stem

posterior communicating artery

branch of the posterior cerebral artery that forms part of the posterior portion of the arterial circle; supplies blood to the brain

posterior tibial artery

branch from the popliteal artery that gives rise to the fibular or peroneal artery; supplies blood to the posterior tibial region

posterior tibial vein

forms from the dorsal venous arch; drains the area near the posterior surface of the tibia and leads to the popliteal vein

precapillary sphincters

circular rings of smooth muscle that surround the entrance to a capillary and regulate blood flow into that capillary

pulmonary artery

one of two branches, left and right, that divides off from the pulmonary trunk and leads to smaller arterioles and eventually to the pulmonary capillaries

pulmonary circuit

system of blood vessels that provide gas exchange via a network of arteries, veins, and capillaries that run from the heart, through the body, and back to the lungs

pulmonary trunk

single large vessel exiting the right ventricle that divides to form the right and left pulmonary arteries

pulmonary veins

two sets of paired vessels, one pair on each side, that are formed from the small venules leading away from the pulmonary capillaries that flow into the left atrium

pulse

alternating expansion and recoil of an artery as blood moves through the vessel; an indicator of heart rate

pulse pressure

difference between the systolic and diastolic pressures

radial artery

formed at the bifurcation of the brachial artery; parallels the radius; gives off smaller branches until it reaches the carpal region where it fuses with the ulnar artery to form the superficial and deep palmar arches; supplies blood to the lower arm and carpal region

radial vein

parallels the radius and radial artery; arises from the palmar venous arches and leads to the brachial vein

reabsorption

in the cardiovascular system, the movement of material from the interstitial fluid into the capillaries

renal artery

branch of the abdominal aorta; supplies each kidney

renal vein

largest vein entering the inferior vena cava; drains the kidneys and leads to the inferior vena cava

resistance

any condition or parameter that slows or counteracts the flow of blood

respiratory pump

increase in the volume of the thorax during inhalation that decreases air pressure, enabling venous blood to flow into the thoracic region, then exhalation increases pressure, moving blood into the atria

right gastric artery

branch of the common hepatic artery; supplies blood to the stomach

sepsis

(also, septicemia) organismal-level inflammatory response to a massive infection

septic shock

(also, blood poisoning) type of shock that follows a massive infection resulting in organism-wide inflammation

sigmoid sinuses

enlarged veins that receive blood from the transverse sinuses; flow through the jugular foramen and into the internal jugular vein

sinusoid capillary

rarest type of capillary, which has extremely large intercellular gaps in the basement membrane in addition to clefts and fenestrations; found in areas such as the bone marrow and liver where passage of large molecules occurs

skeletal muscle pump

effect on increasing blood pressure within veins by compression of the vessel caused by the contraction of nearby skeletal muscle

small saphenous vein

located on the lateral surface of the leg; drains blood from the superficial regions of the lower leg and foot, and leads to the popliteal vein

sphygmomanometer

blood pressure cuff attached to a device that measures blood pressure

splenic artery

branch of the celiac trunk; supplies blood to the spleen

straight sinus

enlarged vein that drains blood from the brain; receives most of the blood from the great cerebral vein and flows into the left or right transverse sinus

subclavian artery

right subclavian arises from the brachiocephalic artery/trunk, whereas the left subclavian artery arises from the aortic arch; gives rise to the internal thoracic, vertebral, and thyrocervical arteries; supplies blood to the arms, chest, shoulders, back, and central nervous system

subclavian vein

located deep in the thoracic cavity; becomes the axillary vein as it enters the axillary region; drains the axillary and smaller local veins near the scapular region; leads to the brachiocephalic vein

subscapular vein

drains blood from the subscapular region and leads to the axillary vein

superior mesenteric artery

branch of the abdominal aorta; supplies blood to the small intestine (duodenum, jejunum, and ileum), the pancreas, and a majority of the large intestine

superior phrenic artery

branch of the thoracic aorta; supplies blood to the superior surface of the diaphragm

superior sagittal sinus

enlarged vein located midsagittally between the meningeal and periosteal layers of the dura mater within the falx cerebri; receives most of the blood drained from the superior surface of the cerebrum and leads to the inferior jugular vein and the vertebral vein

superior vena cava

large systemic vein; drains blood from most areas superior to the diaphragm; empties into the right atrium

systolic pressure

larger number recorded when measuring arterial blood pressure; represents the maximum value following ventricular contraction

temporal vein

drains blood from the temporal region and leads to the external jugular vein

testicular artery

branch of the abdominal aorta; will ultimately travel outside the body cavity to the testes and form one component of the spermatic cord

testicular vein

drains the testes and forms part of the spermatic cord; the right testicular vein empties directly into the inferior vena cava and the left testicular vein empties into the left renal vein

thoracic aorta

portion of the descending aorta superior to the aortic hiatus

thoroughfare channel

continuation of the metarteriole that enables blood to bypass a capillary bed and flow directly into a venule, creating a vascular shunt

thyrocervical artery

arises from the subclavian artery; supplies blood to the thyroid, the cervical region, the upper back, and shoulder

transient ischemic attack (TIA)

temporary loss of neurological function caused by a brief interruption in blood flow; also known as a mini-stroke

transverse sinuses

pair of enlarged veins near the lambdoid suture that drain the occipital, sagittal, and straight sinuses, and leads to the sigmoid sinuses

trunk

large vessel that gives rise to smaller vessels

tunica externa

(also, tunica adventitia) outermost layer or tunic of a vessel (except capillaries)

tunica intima

(also, tunica interna) innermost lining or tunic of a vessel

tunica media

middle layer or tunic of a vessel (except capillaries)

ulnar artery

formed at the bifurcation of the brachial artery; parallels the ulna; gives off smaller branches until it reaches the carpal region where it fuses with the radial artery to form the superficial and deep palmar arches; supplies blood to the lower arm and carpal region

ulnar vein

parallels the ulna and ulnar artery; arises from the palmar venous arches and leads to the brachial vein

vasa vasorum

small blood vessels located within the walls or tunics of larger vessels that supply nourishment to and remove wastes from the cells of the vessels

vascular shock

type of shock that occurs when arterioles lose their normal muscular tone and dilate dramatically

vascular shunt

continuation of the metarteriole and thoroughfare channel that allows blood to bypass the capillary beds to flow directly from the arterial to the venous circulation

vascular tone

contractile state of smooth muscle in a blood vessel

vascular tubes

rudimentary blood vessels in a developing fetus

vasoconstriction

constriction of the smooth muscle of a blood vessel, resulting in a decreased vascular diameter

vasodilation

relaxation of the smooth muscle in the wall of a blood vessel, resulting in an increased vascular diameter

vasomotion

irregular, pulsating flow of blood through capillaries and related structures

vein

blood vessel that conducts blood toward the heart

venous reserve

volume of blood contained within systemic veins in the integument, bone marrow, and liver that can be returned to the heart for circulation, if needed

venule

small vessel leading from the capillaries to veins

vertebral artery

arises from the subclavian artery and passes through the vertebral foramen through the foramen magnum to the brain; joins with the internal carotid artery to form the arterial circle; supplies blood to the brain and spinal cord

vertebral vein

arises from the base of the brain and the cervical region of the spinal cord; passes through the intervertebral foramina in the cervical vertebrae; drains smaller veins from the cranium, spinal cord, and vertebrae, and leads to the brachiocephalic vein; counterpart of the vertebral artery

visceral branches

branches of the descending aorta that supply blood to the viscera

21. Respiratory

acclimatization

process of adjustment that the respiratory system makes due to chronic exposure to high altitudes

acute mountain sickness (AMS)

condition that occurs a result of acute exposure to high altitude due to a low partial pressure of oxygen

ala

(plural = alae) small, flaring structure of a nostril that forms the lateral side of the nares

alar cartilage

cartilage that supports the apex of the nose and helps shape the nares; it is connected to the septal cartilage and connective tissue of the alae

alveolar duct

small tube that leads from the terminal bronchiole to the respiratory bronchiole and is the

point of attachment for alveoli

alveolar macrophage

immune system cell of the alveolus that removes debris and pathogens

alveolar pore

opening that allows airflow between neighboring alveoli

alveolar sac

cluster of alveoli

alveolus

small, grape-like sac that performs gas exchange in the lungs

apex

tip of the external nose

apneustic center

network of neurons within the pons that stimulate the neurons in the dorsal respiratory group; controls the depth of inspiration

atmospheric pressure

amount of force that is exerted by gases in the air surrounding any given surface

Bohr effect

relationship between blood pH and oxygen dissociation from hemoglobin

Boyle’s law

relationship between volume and pressure as described by the formula: P1V1 = P2V2

bridge

portion of the external nose that lies in the area of the nasal bones

bronchial tree

collective name for the multiple branches of the bronchi and bronchioles of the respiratory system

bronchiole

branch of bronchi that are 1 mm or less in diameter and terminate at alveolar sacs

bronchoconstriction

decrease in the size of the bronchiole due to relaxation of the muscular wall

bronchodilation

increase in the size of the bronchiole due to contraction of the muscular wall

bronchus

tube connected to the trachea that branches into many subsidiaries and provides a passageway for air to enter and leave the lungs

carbaminohemoglobin

bound form of hemoglobin and carbon dioxide

carbonic anhydrase (CA)

enzyme that catalyzes the reaction that causes carbon dioxide and water to form carbonic acid

cardiac notch

indentation on the surface of the left lung that allows space for the heart

cellular respiration

production of ATP from glucose oxidation via glycolysis, the Krebs cycle, and oxidative phosphorylation

central chemoreceptor

one of the specialized receptors that are located in the brain that sense changes in hydrogen ion, oxygen, or carbon dioxide concentrations in the brain

conducting zone

region of the respiratory system that includes the organs and structures that provide passageways for air and are not directly involved in gas exchange

cricoid cartilage

portion of the larynx composed of a ring of cartilage with a wide posterior region and a thinner anterior region; attached to the esophagus

Dalton’s law

statement of the principle that a specific gas type in a mixture exerts its own pressure, as if that specific gas type was not part of a mixture of gasses

dorsal respiratory group (DRG)

region of the medulla oblongata that stimulates the contraction of the diaphragm and intercostal muscles to induce inspiration

dorsum nasi

intermediate portion of the external nose that connects the bridge to the apex and is supported by the nasal bone

epiglottis

leaf-shaped piece of elastic cartilage that is a portion of the larynx that swings to close the trachea during swallowing

expiration

(also, exhalation) process that causes the air to leave the lungs

expiratory reserve volume (ERV)

amount of air that can be forcefully exhaled after a normal tidal exhalation

external nose

region of the nose that is easily visible to others

external respiration

gas exchange that occurs in the alveoli

fibroelastic membrane

specialized membrane that connects the ends of the C-shape cartilage in the trachea; contains smooth muscle fibers

forced breathing

(also, hyperpnea) mode of breathing that occurs during exercise or by active thought that requires muscle contraction for both inspiration and expiration

functional residual capacity (FRC)

sum of ERV and RV, which is the amount of air that remains in the lungs after a tidal expiration

glottis

opening between the vocal folds through which air passes when producing speech

Henry’s law

statement of the principle that the concentration of gas in a liquid is directly proportional to the solubility and partial pressure of that gas

hilum

concave structure on the mediastinal surface of the lungs where blood vessels, lymphatic vessels, nerves, and a bronchus enter the lung

hyperpnea

increased rate and depth of ventilation due to an increase in oxygen demand that does not significantly alter blood oxygen or carbon dioxide levels

hyperventilation

increased ventilation rate that leads to abnormally low blood carbon dioxide levels and high (alkaline) blood pH

inspiration

(also, inhalation) process that causes air to enter the lungs

inspiratory capacity (IC)

sum of the TV and IRV, which is the amount of air that can maximally be inhaled past a tidal expiration

inspiratory reserve volume (IRV)

amount of air that enters the lungs due to deep inhalation past the tidal volume

internal respiration

gas exchange that occurs at the level of body tissues

intra-alveolar pressure

(intrapulmonary pressure) pressure of the air within the alveoli

intrapleural pressure

pressure of the air within the pleural cavity

laryngeal prominence

region where the two lamine of the thyroid cartilage join, forming a protrusion known as “Adam’s apple”

laryngopharynx

portion of the pharynx bordered by the oropharynx superiorly and esophagus and trachea inferiorly; serves as a route for both air and food

larynx

cartilaginous structure that produces the voice, prevents food and beverages from entering the trachea, and regulates the volume of air that enters and leaves the lungs

lingual tonsil

lymphoid tissue located at the base of the tongue

Lower respiratory system

include the larynx, trachea, bronchioles, and lungs

lung

organ of the respiratory system that performs gas exchange

meatus

one of three recesses (superior, middle, and inferior) in the nasal cavity attached to the conchae that increase the surface area of the nasal cavity

naris

(plural = nares) opening of the nostrils

nasal bone

bone of the skull that lies under the root and bridge of the nose and is connected to the frontal and maxillary bones

nasal septum

wall composed of bone and cartilage that separates the left and right nasal cavities

nasopharynx

portion of the pharynx flanked by the conchae and oropharynx that serves as an airway

oropharynx

portion of the pharynx flanked by the nasopharynx, oral cavity, and laryngopharynx that is a passageway for both air and food

oxygen–hemoglobin dissociation curve

graph that describes the relationship of partial pressure to the binding and disassociation of oxygen to and from heme

oxyhemoglobin

(Hb–O2) bound form of hemoglobin and oxygen

palatine tonsil

one of the paired structures composed of lymphoid tissue located anterior to the uvula at the roof of isthmus of the fauces

paranasal sinus

one of the cavities within the skull that is connected to the conchae that serve to warm and humidify incoming air, produce mucus, and lighten the weight of the skull; consists of frontal, maxillary, sphenoidal, and ethmoidal sinuses

parietal pleura

outermost layer of the pleura that connects to the thoracic wall, mediastinum, and diaphragm

partial pressure

force exerted by each gas in a mixture of gases

peripheral chemoreceptor

one of the specialized receptors located in the aortic arch and carotid arteries that sense changes in pH, carbon dioxide, or oxygen blood levels

pharyngeal tonsil

structure composed of lymphoid tissue located in the nasopharynx

pharynx

region of the conducting zone that forms a tube of skeletal muscle lined with respiratory epithelium; located between the nasal conchae and the esophagus and trachea

philtrum

concave surface of the face that connects the apex of the nose to the top lip

pleural cavity

space between the visceral and parietal pleurae

pleural fluid

substance that acts as a lubricant for the visceral and parietal layers of the pleura during the movement of breathing

pneumotaxic center

network of neurons within the pons that inhibit the activity of the neurons in the dorsal respiratory group; controls rate of breathing

pulmonary artery

artery that arises from the pulmonary trunk and carries deoxygenated, arterial blood to the

alveoli

pulmonary plexus

network of autonomic nervous system fibers found near the hilum of the lung

pulmonary surfactant

substance composed of phospholipids and proteins that reduces the surface tension of the alveoli; made by type II alveolar cells

pulmonary ventilation

exchange of gases between the lungs and the atmosphere; breathing

quiet breathing

(also, eupnea) mode of breathing that occurs at rest and does not require the cognitive thought of the individual

residual volume (RV)

amount of air that remains in the lungs after maximum exhalation

respiration

A combination of four processes including pulmonary ventilation (movement of air into and out of lungs), external respiration (gas exchange at the lung tissue), transportation of respiratory gases (in the blood), and internal respiration (gas exchange at the body tissues)

respiratory bronchiole

specific type of bronchiole that leads to alveolar sacs

respiratory cycle

one sequence of inspiration and expiration

respiratory epithelium

ciliated lining of much of the conducting zone that is specialized to remove debris and pathogens, and produce mucus

respiratory membrane

alveolar and capillary wall together, which form an air-blood barrier that facilitates the simple diffusion of gases

respiratory rate

total number of breaths taken each minute

respiratory volume

varying amounts of air within the lung at a given time

respiratory zone

includes structures of the respiratory system that are directly involved in gas exchange

root

region of the external nose between the eyebrows

thoracic wall compliance

ability of the thoracic wall to stretch while under pressure

thyroid cartilage

largest piece of cartilage that makes up the larynx and consists of two lamine

tidal volume (TV)

amount of air that normally enters the lungs during quiet breathing

total lung capacity (TLC)

total amount of air that can be held in the lungs; sum of TV, ERV, IRV, and RV

total pressure

sum of all the partial pressures of a gaseous mixture

trachea

tube composed of cartilaginous rings and supporting tissue that connects the lung bronchi and the larynx; provides a route for air to enter and exit the lung

trachealis muscle

smooth muscle located in the fibroelastic membrane of the trachea

transpulmonary pressure

pressure difference between the intrapleural and intra-alveolar pressures

true vocal cord

one of the pair of folded, white membranes that have a free inner edge that oscillates as air passes through to produce sound

type I alveolar cell

squamous epithelial cells that are the major cell type in the alveolar wall; highly permeable to gases

type II alveolar cell

cuboidal epithelial cells that are the minor cell type in the alveolar wall; secrete pulmonary surfactant

Upper respiratory zone

include the nose, nasal cavity, and pharynx

ventilation

movement of air into and out of the lungs; consists of inspiration and expiration

ventral respiratory group (VRG)

region of the medulla oblongata that stimulates the contraction of the accessory muscles involved in respiration to induce forced inspiration and expiration

vestibular fold

part of the folded region of the glottis composed of mucous membrane; supports the epiglottis during swallowing

visceral pleura

innermost layer of the pleura that is superficial to the lungs and extends into the lung fissures

vital capacity (VC)

sum of TV, ERV, and IRV, which is all the volumes that participate in gas exchange

22. Immunology

acquired immunodeficiency syndrome (AIDS)

a serious and lethal disease caused by human immunodeficiency virus (HIV) and characterized by a greatly weakened immune system

active immunity

immunity developed from an individual’s own immune system

adaptive immunity

relatively slow but very specific and effective immune response involving lymphocytes

afferent lymphatic vessels

lead into a lymph node

agglutination

clumping, the amassing of cells due to antibody binding

agranulocytes

WBCs that aren’t granulocytes including monocytes, dendritic cells and lymphocytes

allergens

antigens responsible for type I hypersensitivity

alternative pathway

complement activated by the lack of complement-inhibiting proteins

anchoring filaments

projecting, hair-like structures that prevent lymphatic capillary collapse

angiostrongyliasis

rat lungworm disease, caused by the parasitic nematode Angiostrongylus cantonensis carried by slugs and snails

antibody

antigen-specific protein secreted by plasma cells; immunoglobulin

antigen

molecule recognized by the receptors of B and T lymphocytes

antigenicity

the degree to which an antigen binds a T or B cell receptor

antigen presentation

binding of processed antigen to the protein-binding cleft of a major histocompatibility complex molecule

antihistamine

a drug that counteracts the effects of histamine

antimicrobial peptides

a relatively short chain of amino acids with anti-bacterial, -viral or -fungal properties

antipyretic

fever-reducing medications

APC

an antigen presenting cells, namely macrophages and dendritic cells

artificial immunity

occurs when an antigen is intentionally injected into the body for the sake of generating antibodies and memory lymphocytes such as with vaccines

autoimmune diseases

a pathologic adaptive immune response against your own tissues

bacteria

single-celled, prokaryotic microorganisms

basophil

granulocytes with histidine containing granules and are implicated in allergies

bronchus-associated lymphoid tissue (BALT)

bronchus-associated lymphoid tissue, lymphoid nodule associated with the respiratory tract

B cell

lymphocyte that acts by differentiating into an antibody-secreting plasma cell

C3

complement protein that fragments into C3a and C3b. C3a enhances inflammation and C3b is an opsonin and activates C5

C5

complement protein that fragments into C5a and C5b. C5a enhances inflammation C5b initiates formation of the MAC by triggering the interaction of C6, C7, C8 and several C9s.

CAMs

cell adhesion molecules that promote intercellular binding

CD4+ T cells

Th , helper T cells, T cells that express the surface protein CD4

central tolerance

B cell tolerance induced in immature B cells of the bone marrow

cell-mediated immunity

adaptive immunity activated by helper T cell subclass Th1, involving TC

chemokine

soluble, long-range, cell-to-cell communication molecule

chemotaxis

cells following a chemical concentration gradient such as leukocytes following a chemokine trail toward a site of injury

chyle

lipid-rich lymph inside the lymphatic capillaries of the small intestine

cisterna chyli

bag-like vessel that forms the beginning of the thoracic duct

classical pathway

complement proteins are activated by the presence of pathogen bound antibodies

class switching

ability of B cells to change the class of antibody they produce without altering the

specificity for antigen, aka isotype switching

clonal expansion

proliferation of B lymphocytes with a specific antigen receptor into a population with varying degree of antigen binding strength

complement

enzymatic cascade of constitutive blood proteins that have anti-pathogen effects, including

the direct killing of bacteria

constant region

domain part of a lymphocyte antigen receptor that does not vary much between different

receptor types

COVID-19

coronavirus disease-2019 caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for a worldwide pandemic in the year 2020

C-Reactive Protein (CRP)

a protein associated with stress, inflammation and psychophysiological disorders

CSFs

colony-stimulating factors, induce proliferation of WBCs in the bone marrow

cytokine

soluble, short-range, cell-to-cell communication molecule

cytotoxic T cells (Tc)

T lymphocytes with the ability to induce apoptosis in target cells

DAMPs

damage-associated molecular patterns recognized by PRRs of innate immunity

defensin

a chemical class type of AMPs

delayed hypersensitivity (type IV)

T cell-mediated immune response against pathogens infiltrating interstitial tissues, causing cellular infiltrate

dendritic cell

an APC similar to macrophages

dermcidin

a chemical class type of AMPs

diapedesis

leukocytes squeezing between endothelial, out of the blood into the surrounding tissues

disease

abnormal functioning part of the body, illness, sickness or ailment

effector B cells

plasma cells, activated B lymphocytes

effector T cells

immune cells with a direct, adverse effect on a pathogen

efferent lymphatic vessels

lead out of a lymph node

endemic

a disease common within a popultion

eosinophil

granulocytes specialized for attaching parasites such as worms

epidemic

the rapid spreading or temporary prevalence of disease in a population

epitope

the specific region of an antigen that binds to a T or B cell receptor

erythroblastosis fetalis

disease of Rh factor-positive newborns in Rh-negative mothers with multiple Rh-positive

children; resulting from the action of maternal antibodies against fetal blood

Fab

fragment of antigen binding, that part of the antibody that binds antigen

fas ligand (FasL)

molecule expressed on cytotoxic T cells and NK cells that binds to the fas molecule on a

target cell and induces it do undergo apoptosis

Fc receptor

a membrane bound protein on phagocytes that binds the Fc region of an antibody

Fc region

in an antibody molecule, the site where the two termini of the heavy chains come together;

many cells have receptors for this portion of the antibody, adding functionality to these molecules

fever

abnormally high body temperature, aka pyrexia

fungi

eukaryotic organisms distinguished from animals and plants by chitin-containing cell walls among other features

germinal center

clusters of rapidly proliferating B cells found in secondary lymphoid tissues

granzyme

apoptosis-inducing substance contained in granules of NK cells and cytotoxic T cells

granulocytes

WBCs that have granules; neutrophils, eosinophils and basophils

Grave’s disease

an autoimmune disease causing hyperthyroidism resulting in tachycardia, heat sensitivity, weight loss, eye bulging among other symptoms

Hansen’s disease (leprosy)

a disease caused by a Mycobacterium leprae infection primarily affecting the peripheral nervous system, skin, and nasal mucosa

helper T cells (Th)

T cells that secrete cytokines to enhance other immune responses, involved in

activation of both B and Tc cell lymphocytes

high endothelial venules (HEV)

vessels containing unique endothelial cells specialized to allow migration of

lymphocytes from the blood to the lymph node

histamine

vasoactive mediator in granules of basophils and mast cells and is the primary cause of allergies and anaphylactic shock

human immunodeficiency virus (HIV)

is a virus capable of causing acquired immunodeficiency syndrome (AIDS), a serious and lethal disease characterized by a greatly weakened immune system

humoral immunity

adaptive immunity involving Th2 stimulating B cells to secrete antibodies

hypersomatic mutation

the process of the antigen-binding regions of the B cell receptor (and antibody) to be altered during B cell clonal expansion

hyperemia

increased blood flow near the site of inflammation

hypersensitivity

an excessive, potentially harmful overreaction to an antigen

IgA

antibody whose dimer is secreted by exocrine glands, is especially effective against digestive and respiratory pathogens, and can pass immunity to an infant through breastfeeding

IgD

class of antibody whose only known function is as a receptor on naive B cells; important in B cell activation

IgE

antibody that binds to mast cells and causes antigen-specific degranulation during an allergic response

IgG

main blood antibody of late primary and early secondary responses; passed from carrier to unborn child via placenta

IgM

antibody whose monomer is a surface receptor of naive B cells; the pentamer is the first antibody made blood plasma during primary responses

IL-4

interleukin-4, promotes Th2 and plasma cell development among other functions

immediate hypersensitivity (type I)

IgE-mediated mast cell degranulation caused by crosslinking of surface IgE by antigen

immune system series of barriers, cells, and soluble mediators that combine to response to infections of the body with pathogenic organisms

immunogenicity

the degree by which an antigen induces an immune response

immunoglobulin

protein antibody; occurs as one of five main classes

immunological memory

ability of the adaptive immune response to mount a stronger and faster immune response upon re-exposure to a pathogen

infectious

a disease capable of transmitting from person to person

inflammation

basic innate immune response characterized by heat, redness, pain, and swelling

innate immunity

rapid but relatively nonspecific immune responses

interferons (INFs)

early induced proteins made in virally infected cells that cause nearby cells to make antiviral proteins

interleukins

chemical messengers released by WBCs to stimulate others in an autocrine or paracrine manner

interstitial fluid (IF)

fluid between cells and tissues, excluding plasma or lymph

kinins

peptides that contribute to pain, inflammation and smooth muscle contraction

lacteal

lymphatic capillaries of the gut that absorb bile to form chyle

lectin pathway

complement activated by the presence of certain carbohydrates typical of some bacteria

leukocyte (aka WBC)

white blood cells, cells of the immune system

leukocytosis

a high WBC count

leukopoiesis

leukocyte proliferation in bone marrow

lymph

fluid contained within the lymphatic system

lymph node

one of the bean-shaped organs found associated with the lymphatic vessels

lymphatic capillaries

smallest of the lymphatic vessels and the origin of lymph flow

lymphatic system

network of lymphatic vessels, lymph nodes, and ducts that carries lymph from the tissues and back to the bloodstream.

lymphatic trunks

large lymphatics that collect lymph from smaller lymphatic vessels and empties into the

blood via lymphatic ducts

lymphatic vessels

Lymphatic vasculature that form  from fused smaller lymphatic capillaries, these deliver lymph to and from lymph nodes

lymphocytes

white blood cells characterized by a large nucleus and small rim of cytoplasm

MAC

membrane attack complex, the interaction of C5, C6, C7, C8 and several C9s creates a hole in bacterial membranes disrupting the targeted cell

macrophage

ameboid phagocyte found in several tissues throughout the body

major histocompatibility complex (MHC)

gene cluster whose proteins present antigens to T cells

MALT

mucosa-associated lymphoid tissue, lymphoid tissue associated with the digestive tract and respiratory system

margination

instead of the middle of the blood vessel, cells travel along the wall by sticking and rolling via CAM interactions

mast cell

cell found in the skin and the lining of body cells that contains cytoplasmic granules with

vasoactive mediators such as histamine (similar to basophils)

memory lymphocytes

long-lived T or B cell reserved for future exposure to a pathogen

MHC class I

found on most cells of the body, it binds to the CD8 molecule on T cells

MHC class II

found on macrophages, dendritic cells, and B cells, it binds to CD4 molecules on T cells

MHC polygeny

multiple MHC genes and their proteins found in body cells

MHC polymorphism

multiple alleles for each individual MHC locus

microbiota (aka normal flora)

the typical bacteria, viruses and other microbes associated with healthy populations

mini flaps

openings that allow IF to enter lymphatic capillaries, becoming lymph

monocyte

precursor to macrophages and dendritic cells seen in the blood

naïve lymphocyte

mature B or T cell that has not yet encountered antigen for the first time

natural killer cell (NK)

cytotoxic lymphocyte of innate immune response

natural immunity

the normal exposure to a pathogen or toxin causing an immune response

negative selection

selection against thymocytes in the thymus that react with self-antigen neutralization inactivation of a virus by the binding of specific antibody

neutralization

antibodies blocking disease promoting molecules on a pathogens such as adherence proteins

neutrophil

phagocytic white blood cell recruited from the bloodstream to the site of infection via the

bloodstream

NETs

neutrophil extracellular traps, released DNA that traps and thereby sequestering pathogens

NSAIDs

non-steroidal anti-inflammatory drugs such as aspirin and ibuprofen

opportunistic diseases

pathogens that don’t normally cause disease in healthy individuals but can when the immune system is compromised in some way

opsonization

enhancement of phagocytosis by the binding of antibody or antimicrobial protein

PAMPS

pathogen associated molecular patterns that are recognized by PRRs of the innate immune system

pandemic

an epidemic of a large area such as an entire country, continent, or planet

paresthesia

an abnormal sensation, such as prickling, itching, etc.

passive immunity

transfer of immunity to a pathogen to an individual that lacks immunity to this pathogen

usually by the injection of antibodies

pathogen

a pathology-inducing agent such as certain bacteria, fungi or viruses

pathogenicity

the extent or ability of a pathogen to cause disease

pattern recognition receptor (PRR)

leukocyte receptor that binds to specific cell wall components of different bacterial species

perforin molecule in NK cell and cytotoxic T cell granules that form pores in the membrane of a target cell

perforin

an enzyme that forms holes in the plasma membrane, released by NK and Tc cells

Peyer’s patches

lymphoid follicles associated with distal regions of the small intestine, part of the MALT

phagocyte

a cell capable of phagocytosis, namely neutrophils, macrophages and dendritic cells

phagocytosis

movement of material from the outside to the inside of the cells via vesicles made from

invaginations of the plasma membrane

plasma cell

differentiated B cell that is actively secreting antibody

PMN

polymorphonuclear cells, aka granulocytes

positive selection

selection of thymocytes within the thymus that interact with self, but not non-self, MHC molecules

primary adaptive response

immune system’s response to the first exposure to a pathogen

primary lymphoid organ

site where lymphocytes mature and proliferate; red bone marrow and

thymus gland

prion

a protein folded into an abnormal shape that causes normal proteins to also misfold

prognosis

forecasting the probable outcome of disease including chances of recovery

prostaglandins

lipids associated with inflammation, bronchodilation and many other effects

PRRs (pattern recognition receptors)

receptors on cells of the innate immune system that bind PAMPs and DAMPs

psychoneuroimmunology

study of the connections between the immune, nervous, and endocrine

systems

psychophysiological disorders

diseases whose symptoms are brought about or worsened by stress and emotional factors

pyrexia

abnormally high body temperature, aka fever

pyrogens

chemicals that signal the hypothalamus to increase body temperature

recombination-activating genes (RAGs)

the genes responsible for recombining segments and randomly inserting nucleotides into the variable regions of T and B cell receptor genes

red pulp

areas within the spleen where old, damaged RBCs are broken down

regulatory T cells (Treg, suppressor T cells)

class of CD4 T cells that regulates other T cell responses

respiratory pump

the mechanism by which plasma and lymph is drawn toward the heart due to the low pressure in the thoracic cage created by the respiratory system

rheumatoid arthritis (RA) is an autoimmune disease that causes inflammation, pain, stiffness, and loss of function of the joints

rheumatic fever

an infection with Streptococcus resulting in inflammation heart, skin, joints or brain tissue

right lymphatic duct

drains lymph fluid from the upper right side of body into the right subclavian

vein

secondary adaptive response

immune response observed upon re-exposure to a pathogen, which is

stronger and faster than a primary response

secondary lymphoid organ

sites where lymphocytes mount adaptive immune responses; examples include lymph nodes and spleen

self-antigen

molecules produced by and that do not induce adaptive immune responses of an individual in the absence of autoimmune disease

seroconversion

clearance of pathogen in the serum and the simultaneous rise of serum antibody

systemic lupus erythematosus (SLE)

an autoimmune disease causing inflammation, joint aches, fever, and characteristic skin rashes and swelling

T cell

a cell type of the adaptive immune system, the two main subtypes being TH and Tc

T cell-dependent antigen

antigen that binds to B cells, which requires signals from T cells to make antibody

T cell-independent antigen

binds to B cells, which do not require signals from T cells to make antibody

Th1

cells that secrete cytokines that enhance the activity of Tc

Th2

cells that secrete cytokines that induce B cells to differentiate into plasma cells

thoracic duct

large duct that drains lymph from the lower limbs, left thorax, left upper limb, and the left

side of the head

thymus

primary lymphoid organ; where T lymphocytes proliferate and mature

tonsils

lymphoid nodules associated with the nasopharynx

type I hypersensitivity

immediate response mediated by mast cell degranulation caused by the crosslinking of the antigen-specific IgE molecules on the mast cell surface

type II hypersensitivity

cell damage caused by the binding of antibody and the activation of complement, usually against red blood cells

type III hypersensitivity

damage to tissues caused by the deposition of antibody-antigen (immune) complexes followed by the activation of complement

type IV hypersensitivity (aka delayed hypersensitivity)

an antibody-independent response primarily involving by T cells and macrophages

valves

inward projections within lymphatic capillaries that prevent lymph backflow

variable region

domain part of a lymphocyte antigen receptor that varies considerably between different

receptor types

vasodilation

an increase in blood vessel diameter

virus

a non-living infectious agent that requires a living cell to multiply

white pulp

areas in the spleen where numerous WBCs are performing immunological functions

23. Digestive System

absorption

passage of digested products from the intestinal lumen through mucosal cells and into the bloodstream or lacteals

accessory digestive organ

includes teeth, tongue, salivary glands, gallbladder, liver, and pancreas

accessory duct

(also, duct of Santorini) duct that runs from the pancreas into the duodenum

acinus

cluster of glandular epithelial cells in the pancreas that secretes pancreatic juice in the pancreas

alimentary canal

continuous muscular digestive tube that extends from the mouth to the anus

aminopeptidase

brush border enzyme that acts on proteins

anal canal

final segment of the large intestine

anal column

long fold of mucosa in the anal canal

anal sinus

recess between anal columns

appendix

(vermiform appendix) coiled tube attached to the cecum

ascending colon

first region of the colon

bacterial flora

bacteria in the large intestine

bile

alkaline solution produced by the liver and important for the emulsification of lipids

bile canaliculus

small duct between hepatocytes that collects bile

bilirubin

main bile pigment, which is responsible for the brown color of feces

body

mid-portion of the stomach

bolus

mass of chewed food

brush border

fuzzy appearance of the small intestinal mucosa created by microvilli

cardia

(also, cardiac region) part of the stomach surrounding the cardiac orifice (esophageal hiatus)

cecum

pouch forming the beginning of the large intestine

cementum

bone-like tissue covering the root of a tooth

central vein

vein that receives blood from hepatic sinusoids

cephalic phase

(also, reflex phase) initial phase of gastric secretion that occurs before food enters the stomach

chemical digestion

enzymatic breakdown of food

chief cell

gastric gland cell that secretes pepsinogen

chylomicron

large lipid-transport compound made up of triglycerides, phospholipids, cholesterol, and proteins

chyme

soupy liquid created when food is mixed with digestive juices

circular fold

(also, plica circulare) deep fold in the mucosa and submucosa of the small intestine

colon

part of the large intestine between the cecum and the rectum

common bile duct

structure formed by the union of the common hepatic duct and the gallbladder’s cystic duct

common hepatic duct

duct formed by the merger of the two hepatic ducts

crown

portion of tooth visible superior to the gum line

cuspid

(also, canine) pointed tooth used for tearing and shredding food

cystic duct

duct through which bile drains and enters the gallbladder

deciduous tooth

one of 20 “baby teeth”

defecation

elimination of undigested substances from the body in the form of feces

deglutition

three-stage process of swallowing

dens

tooth

dentin

bone-like tissue immediately deep to the enamel of the crown or cementum of the root of a tooth

dentition

set of teeth

deoxyribonuclease

pancreatic enzyme that digests DNA

descending colon

part of the colon between the transverse colon and the sigmoid colon

dipeptidase

brush border enzyme that acts on proteins

duodenal gland

(also, Brunner’s gland) mucous-secreting gland in the duodenal submucosa

duodenum

first part of the small intestine, which starts at the pyloric sphincter and ends at the jejunum

enamel

covering of the dentin of the crown of a tooth

enteroendocrine cell

gastric gland cell that releases hormones

enterohepatic circulation

recycling mechanism that conserves bile salts

enteropeptidase

intestinal brush-border enzyme that activates trypsinogen to trypsin

epiploic appendage

small sac of fat-filled visceral peritoneum attached to teniae coli

esophagus

muscular tube that runs from the pharynx to the stomach

external anal sphincter

voluntary skeletal muscle sphincter in the anal canal

fauces

opening between the oral cavity and the oropharynx

feces

semisolid waste product of digestion

flatus

gas in the intestine

fundus

dome-shaped region of the stomach above and to the left of the cardia

G cell

gastrin-secreting enteroendocrine cell

gallbladder

accessory digestive organ that stores and concentrates bile

gastric emptying

process by which mixing waves gradually cause the release of chyme into the duodenum

gastric gland

gland in the stomach mucosal epithelium that produces gastric juice

gastric phase

phase of gastric secretion that begins when food enters the stomach

gastric pit

narrow channel formed by the epithelial lining of the stomach mucosa

gastrin

peptide hormone that stimulates secretion of hydrochloric acid and gut motility

gastrocolic reflex

propulsive movement in the colon activated by the presence of food in the stomach

gastroileal reflex

long reflex that increases the strength of segmentation in the ileum

gingiva

gum

haustral contraction

slow segmentation in the large intestine

haustrum

small pouch in the colon created by tonic contractions of teniae coli

hepatic artery

artery that supplies oxygenated blood to the liver

hepatic lobule

hexagonal-shaped structure composed of hepatocytes that radiate outward from a central vein

hepatic portal vein

vein that supplies deoxygenated nutrient-rich blood to the liver

hepatic sinusoid

blood capillaries between rows of hepatocytes that receive blood from the hepatic portal vein and the branches of the hepatic artery

hepatic vein

vein that drains into the inferior vena cava

hepatocytes

major functional cells of the liver

hepatopancreatic ampulla

(also, ampulla of Vater) bulb-like point in the wall of the duodenum where the bile duct and main pancreatic duct unite

hepatopancreatic sphincter

(also, sphincter of Oddi) sphincter regulating the flow of bile and pancreatic juice into the duodenum

hydrochloric acid (HCl)

digestive acid secreted by parietal cells in the stomach

ileocecal sphincter

sphincter located where the small intestine joins with the large intestine

ileum

end of the small intestine between the jejunum and the large intestine

incisor

midline, chisel-shaped tooth used for cutting into food

ingestion

taking food into the GI tract through the mouth

internal anal sphincter

involuntary smooth muscle sphincter in the anal canal

intestinal gland

(also, crypt of Lieberkühn) gland in the small intestinal mucosa that secretes intestinal juice

intestinal juice

mixture of water and mucus that helps absorb nutrients from chyme

intestinal phase

phase of gastric secretion that begins when chyme enters the intestine

intrinsic factor

glycoprotein required for vitamin B12 absorption in the small intestine

jejunum

middle part of the small intestine between the duodenum and the ileum

labial frenulum

midline mucous membrane fold that attaches the inner surface of the lips to the gums

labium

lip

lactase

brush border enzyme that breaks down lactose into glucose and galactose

lacteal

lymphatic capillary in the villi

large intestine

terminal portion of the alimentary canal

laryngopharynx

part of the pharynx that functions in respiration and digestion

left colic flexure

(also, splenic flexure) point where the transverse colon curves below the inferior end of the spleen

lingual frenulum

mucous membrane fold that attaches the bottom of the tongue to the floor of the mouth

lingual lipase

digestive enzyme from glands in the tongue that acts on triglycerides

lipoprotein lipase

enzyme that breaks down triglycerides in chylomicrons into fatty acids and monoglycerides

liver

largest gland in the body whose main digestive function is the production of bile

lower esophageal sphincter

smooth muscle sphincter that regulates food movement from the esophagus to the stomach

main pancreatic duct

(also, duct of Wirsung) duct through which pancreatic juice drains from the pancreas

major duodenal papilla

point at which the hepatopancreatic ampulla opens into the duodenum

maltase

brush border enzyme that breaks down maltose and maltotriose into two and three molecules of glucose, respectively

mass movement

long, slow, peristaltic wave in the large intestine

mastication

chewing

mechanical digestion

chewing, mixing, and segmentation that prepares food for chemical digestion

mesoappendix

mesentery of the appendix

micelle

tiny lipid-transport compound composed of bile salts and phospholipids with a fatty acid and monoacylglyceride core

microvillus

small projection of the plasma membrane of the absorptive cells of the small intestinal mucosa

migrating motility complex

form of peristalsis in the small intestine

mixing wave

unique type of peristalsis that occurs in the stomach

molar

tooth used for crushing and grinding food

motilin

hormone that initiates migrating motility complexes

motility

movement of food through the GI tract

mucosa

innermost lining of the alimentary canal

mucosal barrier

protective barrier that prevents gastric juice from destroying the stomach itself

mucous neck cell

gastric gland cell that secretes a uniquely acidic mucus

muscularis

muscle (skeletal or smooth) layer of the alimentary canal wall

myenteric plexus

(plexus of Auerbach) major nerve supply to alimentary canal wall; controls motility

nucleosidase

brush border enzyme that digests nucleotides

oral cavity

(also, buccal cavity) mouth

oral vestibule

part of the mouth bounded externally by the cheeks and lips, and internally by the gums and teeth

oropharynx

part of the pharynx continuous with the oral cavity that functions in respiration and digestion

palatoglossal arch

muscular fold that extends from the lateral side of the soft palate to the base of the tongue

palatopharyngeal arch

muscular fold that extends from the lateral side of the soft palate to the side of the pharynx

pancreas

accessory digestive organ that secretes pancreatic juice

pancreatic amylase

enzyme secreted by the pancreas that completes the chemical digestion of carbohydrates in the small intestine

pancreatic juice

secretion of the pancreas containing digestive enzymes and bicarbonate

pancreatic lipase

enzyme secreted by the pancreas that participates in lipid digestion

pancreatic nuclease

enzyme secreted by the pancreas that participates in nucleic acid digestion

parietal cell

gastric gland cell that secretes hydrochloric acid and intrinsic factor

parotid gland

one of a pair of major salivary glands located inferior and anterior to the ears

pectinate line

horizontal line that runs like a ring, perpendicular to the inferior margins of the anal sinuses

pepsinogen

inactive form of pepsin

peristalsis

muscular contractions and relaxations that propel food through the GI tract

permanent tooth

one of 32 adult teeth

pharynx

throat

phosphatase

brush border enzyme that digests nucleotides

porta hepatis

“gateway to the liver” where the hepatic artery and hepatic portal vein enter the liver

portal triad

bile duct, hepatic artery branch, and hepatic portal vein branch

premolar

(also, bicuspid) transitional tooth used for mastication, crushing, and grinding food

propulsion

voluntary process of swallowing and the involuntary process of peristalsis that moves food through the digestive tract

pulp cavity

deepest portion of a tooth, containing nerve endings and blood vessels

pyloric antrum

wider, more superior part of the pylorus

pyloric canal

narrow, more inferior part of the pylorus

pyloric sphincter

sphincter that controls stomach emptying

pylorus

lower, funnel-shaped part of the stomach that is continuous with the duodenum

rectal valve

one of three transverse folds in the rectum where feces is separated from flatus

rectum

part of the large intestine between the sigmoid colon and anal canal

reticuloendothelial cell

(also, Kupffer cell) phagocyte in hepatic sinusoids that filters out material from venous blood from the alimentary canal

retroperitoneal

located posterior to the peritoneum

ribonuclease

pancreatic enzyme that digests RNA

right colic flexure

(also, hepatic flexure) point, at the inferior surface of the liver, where the ascending colon turns abruptly to the left

root

portion of a tooth embedded in the alveolar processes beneath the gum line

ruga

fold of alimentary canal mucosa and submucosa in the empty stomach and other organs

saccharolytic fermentation

anaerobic decomposition of carbohydrates

saliva

aqueous solution of proteins and ions secreted into the mouth by the salivary glands

salivary amylase

digestive enzyme in saliva that acts on starch

salivary gland

an exocrine gland that secretes a digestive fluid called saliva

salivation

secretion of saliva

segmentation

alternating contractions and relaxations of non-adjacent segments of the intestine that move food forward and backward, breaking it apart and mixing it with digestive juices

serosa

outermost layer of the alimentary canal wall present in regions within the abdominal cavity

sigmoid colon

end portion of the colon, which terminates at the rectum

small intestine

section of the alimentary canal where most digestion and absorption occurs

soft palate

posterior region of the bottom portion of the nasal cavity that consists of skeletal muscle

stomach

alimentary canal organ that contributes to chemical and mechanical digestion of food from the esophagus before releasing it, as chyme, to the small intestine

sublingual gland

one of a pair of major salivary glands located beneath the tongue

submandibular gland

one of a pair of major salivary glands located in the floor of the mouth

submucosa

layer of dense connective tissue in the alimentary canal wall that binds the overlying mucosa to the underlying muscularis

submucosal plexus

(plexus of Meissner) nerve supply that regulates activity of glands and smooth muscle

sucrase

brush border enzyme that breaks down sucrose into glucose and fructose

tenia coli

one of three smooth muscle bands that make up the longitudinal muscle layer of the muscularis in all of the large intestine except the terminal end

tongue

accessory digestive organ of the mouth, the bulk of which is composed of skeletal muscle

transverse colon

part of the colon between the ascending colon and the descending colon

upper esophageal sphincter

skeletal muscle sphincter that regulates food movement from the pharynx to the esophagus

Valsalva’s maneuver

voluntary contraction of the diaphragm and abdominal wall muscles and closing of the glottis, which increases intra-abdominal pressure and facilitates defecation

villus

projection of the mucosa of the small intestine

voluntary phase

initial phase of deglutition, in which the bolus moves from the mouth to the oropharynx

α-dextrin

breakdown product of starch

α-dextrinase

brush border enzyme that acts on α-dextrins

24. Metabolism

absorptive state

also called the fed state; the metabolic state occurring during the first few hours after ingesting food in which the body is digesting food and absorbing the nutrients

acetyl coenzyme A (acetyl CoA)

starting molecule of the Krebs cycle

anabolic hormones

hormones that stimulate the synthesis of new, larger molecules

anabolic reactions

reactions that build smaller molecules into larger molecules

ATP synthase

protein pore complex that creates ATP

basal metabolic rate (BMR)

amount of energy expended by the body at rest

beta (β)-hydroxybutyrate

primary ketone body produced in the body

beta (β)-oxidation

fatty acid oxidation

bile salts

salts that are released from the liver in response to lipid ingestion and surround the insoluble triglycerides to aid in their conversion to monoglycerides and free fatty acids

biosynthesis reactions

reactions that create new molecules, also called anabolic reactions

body mass index (BMI)

relative amount of body weight compared to the overall height; a BMI ranging from 18–24.9 is considered normal weight, 25–29.9 is considered overweight, and greater than 30 is considered obese

calorie

amount of heat it takes to raise 1 kg (1000 g) of water by 1 °C

catabolic hormones

hormones that stimulate the breakdown of larger molecules

catabolic reactions

reactions that break down larger molecules into their constituent parts

cellular respiration

production of ATP from glucose oxidation via glycolysis, the Krebs cycle, and oxidative phosphorylation

cholecystokinin (CCK)

hormone that stimulates the release of pancreatic lipase and the contraction of the gallbladder to release bile salts

chylomicrons

vesicles containing cholesterol and triglycerides that transport lipids out of the intestinal cells and into the lymphatic and circulatory systems

chymotrypsin

pancreatic enzyme that digests protein

chymotrypsinogen

proenzyme that is activated by trypsin into chymotrypsin

citric acid cycle

also called the Krebs cycle or the tricarboxylic acid cycle; converts pyruvate into CO2 and high-energy FADH2, NADH, and ATP molecules

conduction

transfer of heat through physical contact

convection

transfer of heat between the skin and air or water

elastase

pancreatic enzyme that digests protein

electron transport chain (ETC)

ATP production pathway in which electrons are passed through a series of oxidation-reduction reactions that forms water and produces a proton gradient

energy-consuming phase

first phase of glycolysis, in which two molecules of ATP are necessary to start the reaction

energy-yielding phase

second phase of glycolysis, during which energy is produced

enterokinase

enzyme located in the wall of the small intestine that activates trypsin

evaporation

transfer of heat that occurs when water changes from a liquid to a gas

FADH2

high-energy molecule needed for glycolysis

fatty acid oxidation

breakdown of fatty acids into smaller chain fatty acids and acetyl CoA

flavin adenine dinucleotide (FAD)

coenzyme used to produce FADH2

glucokinase

cellular enzyme, found in the liver, which converts glucose into glucose-6-phosphate upon uptake into the cell

gluconeogenesis

process of glucose synthesis from pyruvate or other molecules

glucose-6-phosphate

phosphorylated glucose produced in the first step of glycolysis

glycogen

form that glucose assumes when it is stored

glycolysis

series of metabolic reactions that breaks down glucose into pyruvate and produces ATP

hexokinase

cellular enzyme, found in most tissues, that converts glucose into glucose-6-phosphate upon uptake into the cell

hydroxymethylglutaryl CoA (HMG CoA)

molecule created in the first step of the creation of ketone bodies from acetyl CoA

inactive proenzymes

forms in which proteases are stored and released to prevent the inappropriate digestion of the native proteins of the stomach, pancreas, and small intestine

insulin

hormone secreted by the pancreas that stimulates the uptake of glucose into the cells

ketone bodies

alternative source of energy when glucose is limited, created when too much acetyl CoA is created during fatty acid oxidation

Krebs cycle

also called the citric acid cycle or the tricarboxylic acid cycle, converts pyruvate into CO2 and high-energy FADH2, NADH, and ATP molecules

lipogenesis

synthesis of lipids that occurs in the liver or adipose tissues

lipolysis

breakdown of triglycerides into glycerol and fatty acids

metabolic rate

amount of energy consumed minus the amount of energy expended by the body

metabolism

sum of all catabolic and anabolic reactions that take place in the body

minerals

inorganic compounds required by the body to ensure proper function of the body

monoglyceride molecules

lipid consisting of a single fatty acid chain attached to a glycerol backbone

monosaccharide

smallest, monomeric sugar molecule

NADH

high-energy molecule needed for glycolysis

nicotinamide adenine dinucleotide (NAD)

coenzyme used to produce NADH

oxidation

loss of an electron

oxidation-reduction reaction

(also, redox reaction) pair of reactions in which an electron is passed from one molecule to another, oxidizing one and reducing the other

oxidative phosphorylation

process that converts high-energy NADH and FADH2 into ATP

pancreatic lipases

enzymes released from the pancreas that digest lipids in the diet

pepsin

enzyme that begins to break down proteins in the stomach

polysaccharides

complex carbohydrates made up of many monosaccharides

postabsorptive state

also called the fasting state; the metabolic state occurring after digestion when food is no longer the body’s source of energy and it must rely on stored glycogen

proteolysis

process of breaking proteins into smaller peptides

pyruvate

three-carbon end product of glycolysis and starting material that is converted into acetyl CoA that enters the Krebs cycle

radiation

transfer of heat via infrared waves

reduction

gaining of an electron

salivary amylase

digestive enzyme that is found in the saliva and begins the digestion of carbohydrates in the mouth

secretin

hormone released in the small intestine to aid in digestion

sodium bicarbonate

anion released into the small intestine to neutralize the pH of the food from the stomach

terminal electron acceptor

oxygen, the recipient of the free hydrogen at the end of the electron transport chain

thermoneutral

external temperature at which the body does not expend any energy for thermoregulation, about 84 °F

thermoregulation

process of regulating the temperature of the body

transamination

transfer of an amine group from one molecule to another as a way to turn nitrogen waste into ammonia so that it can enter the urea cycle

tricarboxylic acid cycle (TCA)

also called the Krebs cycle or the citric acid cycle; converts pyruvate into CO2 and high-energy FADH2, NADH, and ATP molecules

triglycerides

lipids, or fats, consisting of three fatty acid chains attached to a glycerol backbone

trypsin

pancreatic enzyme that activates chymotrypsin and digests protein

trypsinogen

proenzyme form of trypsin

urea cycle

process that converts potentially toxic nitrogen waste into urea that can be eliminated through the kidneys

vitamins

organic compounds required by the body to perform biochemical reactions like metabolism and bone, cell, and tissue growth

25. Urinary System

albuminuria

excessive albumin detected in the urine

adiate arteries

division of the arcuate arteries

afferent arterioles

division of the adiate arteries that supply blood to about 1.3 million nephrons each in the kidney

angiotensin II

protein produced by the enzymatic action of ACE on inactive angiotensin I; actively causes vasoconstriction and stimulates aldosterone release by the adrenal cortex

anuria

absence of urine produced; production of 50 mL or less per day

arcuate arteries

division of the interlobar arteries

aquaporin

protein-forming water channels through the lipid bilayer of the cell; allows water to cross; activation in the collecting ducts is under the control of ADH

Bowman’s capsule

cup-shaped sack lined by a simple squamous epithelium (parietal surface) and specialized cells called podocytes (visceral surface) that participate in the filtration process; receives the filtrate which then passes on to the PCTs

calyces

cup-like structures receiving urine from the collecting ducts where it passes on to the renal pelvis and ureter

cortical nephrons

nephrons with loops of Henle that do not extend into the renal medulla

countercurrent multiplier system

involves the descending and ascending loops of Henle directing forming urine in opposing directions to create a concentration gradient when combined with variable permeability and sodium pumping

detrusor muscle

smooth muscle in the bladder wall; fibers run in all directions to reduce the size of the organ when emptying it of urine

dialysis process to artificially filter blood

distal convoluted tubules

portions of the nephron distal to the loop of Henle that receive hyposmotic filtrate from the loop of Henle and empty into collecting ducts

efferent arteriole

arteriole carrying blood from the glomerulus to the capillary beds around the convoluted tubules and loop of Henle; portion of the portal system

external urinary sphincter

skeletal muscle; must be relaxed consciously to void urine

external urethral orifice

opening of the urethra to the exterior located between the clitoris and the vaginal opening

fenestrations

small windows through a cell, allowing rapid filtration based on size; formed in such a way as to allow substances to cross through a cell without mixing with cell contents

filtration

the first step in the production of urine. Water and solutes in the blood plasma move across the walls of the glomerular capillaries and move into the renal tubules

filtration slits

formed by pedicels of podocytes; substances filter between the pedicels based on size

glomerular filtration rate (GFR)

rate of renal filtration

glomerulus

tuft of capillaries surrounded by Bowman’s capsule; filters the blood based on size

glycosuria

presence of glucose in the urine; caused by high blood glucose levels that exceed the ability of the kidneys to reabsorb the glucose; usually the result of untreated or poorly controlled diabetes mellitus

Hematuria

presence of erythrocytes in urine

incontinence

loss of ability to control micturition

intercalated cell

specialized cell of the collecting ducts that secrete or absorb acid or bicarbonate; important in acid–base balance

interlobar arteries division of the segmental arteries that pass through the renal columns to reach the cortex

internal urinary sphincter

smooth muscle at the juncture of the bladder and urethra; relaxes as the bladder fills to allow urine into the urethra

juxtaglomerular apparatus (JGA)

located at the juncture of the DCT and the afferent and efferent arterioles of the glomerulus; plays a role in the regulation of renal blood flow and GFR

juxtaglomerular cell

modified smooth muscle cells of the afferent arteriole; secretes renin in response to a drop in blood pressure

juxtamedullary nephrons

nephrons adjacent to the border of the cortex and medulla with loops of Henle that extend into the renal medulla

kidneys

main organ of the urinary system where blood is filtered, and the filtrate is transformed into urine at a constant rate throughout the day

ketonuria

high levels of ketone bodies in urine

leukocyte esterase

enzyme produced by leukocytes that can be detected in the urine and that serves as an indirect indicator of urinary tract infection

loop of Henle

descending and ascending portions between the proximal and distal convoluted tubules; those of cortical nephrons do not extend into the medulla, whereas those of juxtamedullary nephrons do extend into the medulla

macula densa

cells found in the part of the DCT forming the JGA; sense Na+ concentration in the forming urine

medulla

inner region of kidney containing the renal pyramids

membranous urethra

portion of male urethra that passes through the deep muscles of the perineum

mesangial

contractile cells found in the glomerulus; can contract or relax to regulate filtration rate

micturition

also called urination or voiding

myogenic mechanism

mechanism by which smooth muscle responds to stretch by contracting; an increase in blood pressure causes vasoconstriction and a decrease in blood pressure causes vasodilation so that blood flow downstream remains steady

nephrons

functional units of the kidney that carry out all filtration and modification to produce urine; consist of renal corpuscles, proximal and distal convoluted tubules, and descending and ascending loops of Henle; drain into collecting ducts

net filtration pressure (NFP)

pressure of fluid across the glomerulus; calculated by taking the hydrostatic pressure of the capillary and subtracting the colloid osmotic pressure of the blood and the hydrostatic pressure of Bowman’s capsule

oliguria

below normal urine production of 400–500 mL/day

osteomalacia

softening of bones due to a lack of mineralization with calcium and phosphate; most often due to lack of vitamin D; in children, osteomalacia is termed rickets; not to be confused with osteoporosis

pedicels

finger-like projections of podocytes surrounding glomerular capillaries; interdigitate to form a filtration membrane

peritubular capillaries

second capillary bed of the renal portal system; surround the proximal and distal convoluted tubules; associated with the vasa recta

podocytes

cells forming finger-like processes; form the visceral layer of Bowman’s capsule; pedicels of the podocytes interdigitate to form a filtration membrane

polyuria

urine production in excess of 2.5 L/day; may be caused by diabetes insipidus, diabetes mellitus, or excessive use of diuretics

principal cell

found in collecting ducts and possess channels for the recovery or loss of sodium and potassium; under the control of aldosterone; also have aquaporin channels under ADH control to regulate recovery of water

prostatic urethra

portion of male urethra that passes through the prostate gland

proximal convoluted tubules (PCTs)

tortuous tubules receiving filtrate from Bowman’s capsule; most active part of the nephron in reabsorption and secretion

pyuria

presence of leukocytes and other components of pus in the urine

Reabsorption

occurs throughout the nephron tubules through to the collecting ducts. Reabsorption is the process where water and solutes return to the blood as it flows through the peritubular capillaries and vasa recta

Renal artery

large blood vessel that brings blood into the kidney

renal columns

extensions of the renal cortex into the renal medulla; separates the renal pyramids; contains blood vessels and connective tissues

renal corpuscle

consists of the glomerulus and Bowman’s capsule

renal cortex

outer part of kidney containing all of the nephrons; some nephrons have loops of Henle extending into the medulla

renal fat pad

adipose tissue between the renal fascia and the renal capsule that provides protective cushioning to the kidney

renal hilum

recessed medial area of the kidney through which the renal artery, renal vein, ureters, lymphatics, and nerves pass

renal papillae

medullary area of the renal pyramids where collecting ducts empty urine into the minor calyces

renal pyramids

six to eight cone-shaped tissues in the medulla of the kidney containing collecting ducts and the loops of Henle of juxtamedullary nephrons

renin

enzyme produced by juxtaglomerular cells in response to decreased blood pressure or sympathetic nervous activity; catalyzes the conversion of angiotensinogen into angiotensin I

retroperitoneal

behind the peritoneum; in the case of the kidney and ureters, between the parietal peritoneum and the abdominal wall

secretion

occurs throughout the nephron tubules to the collecting ducts. Secretion is the process where materials such as wastes, drugs, and excess ions are released from the blood into the filtrate within the tubules

segmental arteries

division of the renal artery

specific gravity

weight of a liquid compared to pure water, which has a specific gravity of 1.0; any solute added to water will increase its specific gravity

spongy urethra

longest portion of the male urethra that passes through the penis and exits at the tip of the penis

trigone

area at the base of the bladder marked by the two ureters in the posterior–lateral aspect and the urethral orifice in the anterior aspect oriented like points on a triangle

tubuloglomerular feedback

feedback mechanism involving the JGA; macula densa cells monitor Na+ concentration in the terminal portion of the ascending loop of Henle and act to cause vasoconstriction or vasodilation of afferent and efferent arterioles to alter GFR

Ureters

transport urine from the kidneys to the urinary bladder

urethra

transports urine from the bladder to the outside environment

urinary bladder

temporarily stores urine until it is ready to be eliminated

urinary tract

contains the kidneys, ureter, urinary bladder, and urethra. Transport, store, and eliminate urine from the body

urinalysis

analysis of urine to diagnose disease

urochrome

heme-derived pigment that imparts the typical yellow color of urine

vasa recta

branches of the efferent arterioles that parallel the course of the loops of Henle and are continuous with the peritubular capillaries; with the glomerulus, form a portal system

26. Electrolytes and Fluids

antidiuretic hormone (ADH)

also known as vasopressin, a hormone that increases the volume of water reabsorbed from the collecting tubules of the kidney

dehydration

state of containing insufficient water in blood and other tissues

diuresis

excess production of urine

extracellular fluid (ECF)

fluid exterior to cells; includes the interstitial fluid, blood plasma, and fluids found in other reservoirs in the body

fluid compartment

fluid inside all cells of the body constitutes a compartment system that is largely segregated from other systems

hypercalcemia

abnormally increased blood levels of calcium

hypercapnia

abnormally elevated blood levels of CO2

hyperchloremia

higher-than-normal blood chloride levels

hyperkalemia

higher-than-normal blood potassium levels

hypermagnesemia

higher-than-normal blood magnesium levels

hypernatremia

abnormal increase in blood sodium levels

hyperphosphatemia

abnormally increased blood phosphate levels

hypocalcemia

abnormally low blood levels of calcium

hypocapnia

abnormally low blood levels of CO2

hypochloremia

lower-than-normal blood chloride levels

hypokalemia

abnormally decreased blood levels of potassium

hypomagnesemia

lower-than-normal blood magnesium levels

hyponatremia

lower-than-normal levels of sodium in the blood

hypophosphatemia

abnormally low blood phosphate levels

interstitial fluid (IF)

fluid in the small spaces between cells not contained within blood vessels

intracellular fluid (ICF)

fluid in the cytosol of cells

metabolic acidosis

condition wherein a deficiency of bicarbonate causes the blood to be overly acidic

metabolic alkalosis

condition wherein an excess of bicarbonate causes the blood to be overly alkaline

plasma osmolality

ratio of solutes to a volume of solvent in the plasma; plasma osmolality reflects a person’s state of hydration

respiratory acidosis

condition wherein an excess of carbonic acid or CO2 causes the blood to be overly acidic

respiratory alkalosis

condition wherein a deficiency of carbonic acid/CO2 levels causes the blood to be overly alkaline

27. Reproduction

alveoli

(of the breast) milk-secreting cells in the mammary gland

ampulla

(of the uterine tube) middle portion of the uterine tube in which fertilization often occurs

antrum

fluid-filled chamber that characterizes a mature tertiary (antral) follicle

areola

highly pigmented, circular area surrounding the raised nipple and containing areolar glands that secrete fluid important for lubrication during suckling

blood–testis barrier

tight junctions between Sertoli cells that prevent bloodborne pathogens from gaining access to later stages of spermatogenesis and prevent the potential for an autoimmune reaction to haploid sperm

body of uterus

middle section of the uterus

bulbourethral glands

(also, Cowper’s glands) glands that secrete a lubricating mucus that cleans and lubricates the urethra prior to and during ejaculation

cervix

elongate inferior end of the uterus where it connects to the vagina

clitoris

(also, glans clitoris) nerve-rich area of the vulva that contributes to sexual sensation during intercourse

corpus albicans

nonfunctional structure remaining in the ovarian stroma following structural and functional regression of the corpus luteum

corpus cavernosum

either of two columns of erectile tissue in the penis that fill with blood during an erection

corpus luteum

transformed follicle after ovulation that secretes progesterone

corpus spongiosum

(plural = corpora cavernosa) column of erectile tissue in the penis that fills with blood during an erection and surrounds the penile urethra on the ventral portion of the penis

cremaster muscle

surrounds each testis like a muscular sling; contracts to elevate the testes when exposed to cold

dartos muscle

subcutaneous muscle layer of the scrotum; capable of tightening and wrinkling the scrotum when exposed to cold

diploid

having two complete sets of chromosomes

ductus deferens

(also, vas deferens) duct that transports sperm from the epididymis through the spermatic cord and into the ejaculatory duct; also referred as the vas deferens

ejaculatory duct

duct that connects the ampulla of the ductus deferens with the duct of the seminal vesicle at the prostatic urethra

endometrium

inner lining of the uterus, part of which builds up during the secretory phase of the menstrual cycle and then sheds with menses

epididymis

(plural = epididymides) coiled tubular structure in which sperm start to mature and are stored until ejaculation

fertilization

a sperm combines with an oocyte

fimbriae

fingerlike projections on the distal uterine tubes

follicle

ovarian structure of one oocyte and surrounding granulosa (and later theca) cells

folliculogenesis

development of ovarian follicles from primordial to tertiary under the stimulation of gonadotropins

fundus

(of the uterus) domed portion of the uterus that is superior to the uterine tubes

gamete

haploid reproductive cell that contributes genetic material to form an offspring

glans penis

bulbous end of the penis that contains a large number of nerve endings

gonads

reproductive organs (testes in men and ovaries in women) that produce gametes and reproductive hormones

granulosa cells

supportive cells in the ovarian follicle that produce estrogen

greater vestibular glands

(also, Bartholin’s glands) glands that produce a thick mucus that maintains moisture in the vulva area

haploid

having a single set of unpaired chromosomes

homologous

similar in function, location, and/or structure; derived from the same embryological structure

hymen

membrane that covers part of the opening of the vagina

infundibulum

(of the uterine tube) wide, distal portion of the uterine tube terminating in fimbriae

inguinal canal

opening in abdominal wall that connects the testes to the abdominal cavity

isthmus

narrow, medial portion of the uterine tube that joins the uterus; narrow region of the body of the uterus superior to the cervix

labia majora

hair-covered folds of skin located behind the mons pubis

labia minora

thin, pigmented, hairless flaps of skin located medial to the labia majora

lactiferous ducts

ducts that connect the mammary glands to the nipple and allow for the transport of milk

lactiferous sinus

area of milk collection between alveoli and lactiferous duct

interstitial endocrine cells

(also Leydig cells) cells between the seminiferous tubules of the testes that produce testosterone

mammary glands

glands inside the breast that secrete milk

meiosis

type of cell division that makes daughter cells with half as many chromosomes as the parent cell; type of cell division for gamete production

menarche

first menstruation in a pubertal female

menopause

the natural decline in female reproductive hormones and the ceasing of menstrual periods

menses

shedding of the inner portion of the endometrium out though the vagina; also referred to as menstruation or menstrual period

menses phase

phase of the menstrual cycle in which the endometrial lining is shed

menstrual cycle

approximately 28-day cycle of changes in the uterus consisting of a menses phase, a proliferative phase, and a secretory phase

mitosis

type of cell division that makes daughter cells that are identical to the parent cell; common type of cell division for tissue growth

mons pubis

mound of fatty tissue located at the front of the vulva

myometrium

smooth muscle layer of uterus that allows for uterine contractions during labor and expulsion of menstrual blood

oocyte

cell that results from the division of the oogonium and undergoes meiosis I at the LH surge and meiosis II at fertilization to become a haploid ovum

oogenesis

process by which oogonia divide by mitosis to primary oocytes, which undergo meiosis to produce the secondary oocyte and, upon fertilization, the ovum

oogonia

ovarian stem cells that undergo mitosis during female fetal development to form primary oocytes

ovarian cycle

approximately 28-day cycle of changes in the ovary consisting of a follicular phase and a luteal phase

ovaries

female gonads that produce oocytes and sex steroid hormones (notably estrogen and progesterone)

ovulation

release of a secondary oocyte and associated granulosa cells from an ovary

ovum

haploid female gamete resulting from completion of meiosis II at fertilization

paraurethral glands

structures that open laterally to the female external urethral orifice and secrete mucus

penis

male organ of sexual intercourse

perimetrium

outer epithelial layer of uterine wall

polar body

smaller cell produced during the process of meiosis in oogenesis

prepuce

(also, foreskin) flap of skin that forms a collar around, and thus protects and lubricates, the glans penis

primary follicles

ovarian follicles with a primary oocyte and one layer of cuboidal granulosa cells

primordial follicles

least developed ovarian follicles that consist of a single oocyte and a single layer of flat (squamous) granulosa cells

proliferative phase

phase of the menstrual cycle in which the endometrium proliferates

prostate gland

doughnut-shaped gland at the base of the bladder surrounding the urethra and contributing fluid to semen during ejaculation

puberty

life stage during which a male or female adolescent becomes anatomically and physiologically capable of reproduction

rugae

(of the vagina) folds of skin in the vagina that allow it to stretch during intercourse and childbirth

scrotum

external pouch of skin and muscle that houses the testes

secondary follicles

ovarian follicles with a primary oocyte and multiple layers of granulosa cells

secondary sex characteristics

physical characteristics that are influenced by sex steroid hormones and have supporting roles in reproductive function

secretory phase

phase of the menstrual cycle in which the endometrium secretes a nutrient-rich fluid in preparation for implantation of an embryo

semen

ejaculatory fluid composed of sperm and secretions from the seminal vesicles, prostate, and bulbourethral glands

seminal vesicle

gland that produces seminal fluid, which contributes to semen

seminiferous tubules

tube structures within the testes where spermatogenesis occurs

Sertoli cells

(also, nurse cells and sustentacular cells) cells that support germ cells through the process of spermatogenesis

sperm

(also, spermatozoon (plural spermatozoa)) male gamete

spermatic cord

bundle of nerves and blood vessels that supplies the testes; contains ductus deferens

spermatid

immature sperm cells produced by meiosis II of secondary spermatocytes

spermatocyte

cell that results from the division of spermatogonium and undergoes meiosis I and meiosis II to form spermatids

spermatogenesis

formation of new sperm, occurs in the seminiferous tubules of the testes

spermatogonia

(singular = spermatogonium) diploid precursor cells that become sperm

spermiogenesis

transformation of spermatids to spermatozoa during spermatogenesis

tertiary follicles

(also, antral follicles) ovarian follicles with a primary or secondary oocyte, multiple layers of granulosa cells, and a fully formed antrum

testes

(singular = testis) male gonads

theca cells

estrogen-producing cells in a maturing ovarian follicle

uterine tubes

(also, fallopian tubes or oviducts) ducts that facilitate transport of an ovulated oocyte to the uterus

uterus

muscular hollow organ in which a fertilized egg develops into a fetus

vagina

tunnel-like organ that provides access to the uterus for the insertion of semen and from the uterus for the birth of a baby

vulva

external female genitalia

28. Development