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
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