Glossary
G-9
Fibrillation
Condition of rapid and irregular or out-of-phase heart con-
tractions.
Fibrin
(fi
9
brin) Fibrous insoluble protein formed during blood clotting.
Fibrinogen
(fi-brin
9
o-jin) A soluble blood protein that is converted to
insoluble fibrin during blood clotting.
Fibrinolysis
Process that removes unneeded blood clots when healing
has occurred.
Fibroblast
(fi
9
bro-blast) Young, actively mitotic cell that forms the fibers
of connective tissue.
Fibrocartilage
Te most compressible type of cartilage; resistant to
stretch. Forms vertebral discs and knee joint cartilages.
Fibrocyte
(fi
9
bro-sīt) Mature fibroblast; maintains the matrix of fibrous
types of connective tissue.
Fibrosis
Proliferation of fibrous connective tissue called scar tissue.
Fibrous joints
Bones joined by fibrous tissue; no joint cavity is present.
Filtrate
A plasma-derived fluid that is processed by the renal tubules to
form urine.
Filtration
Passage of a solvent and dissolved substances through a mem-
brane or filter.
First-degree burn
A burn in which only the epidermis is damaged.
Fissure
(fih
9
sher) (1) A groove or cle±; (2) the deepest depressions or
inward folds on the brain.
Fixator
(fix
9
a-ter) Muscle that immobilizes one or more bones, allowing
other muscles to act from a stable base.
Flagellum
(flah-jel
9
lum) Long, whiplike cellular extension containing
microtubules; propels sperm and some single-celled eukaryotes.
Flexion
(flek
9
shun) Movement that decreases the angle of the joint, e.g.,
bending the knee from a straight to an angled position.
Flexor (withdrawal) reflex
Reflex initiated by a painful stimulus (actual
or perceived); causes automatic withdrawal of the threatened body part
from the stimulus.
Fluid mosaic model
A depiction of the structure of the membranes of a
cell as phospholipid bilayers in which proteins are dispersed.
Follicle
(fah
9
lih-kul) (1) Ovarian structure consisting of a developing egg
surrounded by one or more layers of follicle cells; (2) colloid-containing
structure of the thyroid gland; (3) B cell–rich region in lymphoid tissue.
Follicle-stimulating hormone (FSH)
Hormone produced by the ante-
rior pituitary that stimulates ovarian follicle production in females and
sperm production in males.
Fontanelles
(fon
0
tah-nelz
9
) Fibrous membranes at the angles of cranial
bones that accommodate brain growth in the fetus and infant.
Foramen
(fo-ra
9
men) Hole or opening in a bone or between body cavities.
Forebrain (prosencephalon)
Anterior portion of the brain consisting of
the telencephalon and the diencephalon.
Formed elements
Cellular portion of blood.
Fossa
(fos
9
ah) A depression, o±en an articular surface.
Fovea
(fo
9
ve-ah) A pit.
Fracture
A break in a bone.
Free radicals
Highly reactive chemicals with unpaired electrons that can
scramble the structure of proteins, lipids, and nucleic acids.
Frontal (coronal) plane
Longitudinal (vertical) plane that divides the
body or an organ into anterior and posterior parts.
Fulcrum
Te fixed point on which a lever moves when a force is applied.
Fundus
(fun
9
dus) Base of an organ; part farthest from the opening of the
organ. For example, the posterior wall of the eye.
Estrogens
(es
9
tro-jenz) Hormones that stimulate female secondary sex
characteristics; female sex hormones.
Eupnea
(ūp-ne
9
ah) Normal respiratory rate and rhythm.
Excess postexercise oxygen consumption (EPOC)
Te volume of oxy-
gen required a±er exercise to replenish stores of O
2
, A²P, creatine phos-
phate, and glycogen and oxidize the lactic acid formed during exercise.
Also called oxygen debt.
Exchange (displacement) reaction
Chemical reaction in which bonds are
both made and broken; atoms become combined with different atoms.
Excitability (responsiveness)
Ability to respond to stimuli.
Excitation-contraction (E-C) coupling
Sequence of events by which
transmission of an action potential along the sarcolemma leads to the
sliding of myofilaments.
Excitatory postsynaptic potential (EPSP)
Depolarizing graded poten-
tial in a postsynaptic neuron.
Excretion
(ek-skre
9
shun) Elimination of waste products from the body.
Exergonic reaction
Chemical reaction that releases energy, e.g., a cata-
bolic or oxidative reaction.
Exocrine glands
(ek
9
so-krin) Glands that have ducts through which
their secretions are carried to a particular site.
Exocytosis
(ek
0
so-si-to
9
sis) Mechanism by which substances are moved
from the cell interior to the extracellular space as a secretory vesicle fuses
with the plasma membrane.
Exons
Amino acid–specifying informational sequences (separated by
introns) in the genes of higher organisms.
Extension
Movement that increases the angle of a joint, e.g., straighten-
ing a flexed knee.
Exteroceptor
(ek
0
ster-o-sep
9
tor) Sensory receptor that responds to
stimuli from the external world.
Extracellular fluid (ECF)
Internal fluid located outside cells; includes
interstitial fluid, blood plasma, and cerebrospinal fluid.
Extracellular matrix
Nonliving material in connective tissue consisting
of ground substance and fibers that separates the living cells.
Extrasystole
(ek
0
strah-sis
9
to-le) Premature heart contraction.
Extrinsic
(ek-strin
9
sik) Of external origin.
Extrinsic eye muscles
Te six skeletal muscles that attach to and move
each eye.
Facilitated diffusion
Passive transport process used by certain large or
charged molecules (e.g., glucose, Na
1
) that are unable to pass through
the plasma membrane unaided. Involves movement through channels or
movement facilitated by a membrane carrier.
Fallopian tube
(fah-lō
9
pe-un)
See
Uterine tube.
Fascia
(fash
9
e-ah) Layers of fibrous tissue covering and separating muscle.
Fascicle
(fas
9
ĭ-kl) Bundle of nerve or muscle fibers bound together by
connective tissue.
Fatty acids
Linear chains of carbon and hydrogen atoms (hydrocarbon
chains) with an organic acid group at one end. A constituent of fat.
Feces
(fe
9
sēz) Material discharged from the bowel; composed of food
residue, secretions, bacteria.
Fenestrated
(fen
9
es-tra-tid) Pierced with one or more small openings.
Fertilization
Fusion of the sperm and egg nuclei.
Fetus
Developmental stage extending from the ninth week of develop-
ment to birth.
Fiber
A slender threadlike structure or filament.
See also
Nerve fiber,
Muscle fiber.
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