G-6
Glossary
Contraception
Te prevention of conception; birth control.
Contractility
Muscle cell’s ability to move by shortening.
Contraction
±o shorten or develop tension, an ability highly developed
in muscle cells.
Contralateral
Relating to the opposite side.
Cornea
(kor
9
ne-ah) ±ransparent anterior portion of the eyeball; part of
the fibrous layer.
Corona radiata
(kor-o
9
nah ra-de-ah
9
tah) (1) Arrangement of elongated
follicle cells around a mature ovum; (2) crownlike arrangement of nerve
fibers radiating from the internal capsule of the brain to every part of the
cerebral cortex.
Coronary circulation
Te functional blood supply of the heart; shortest
circulation in the body.
Cortex
(kor
9
teks) Outer surface layer of an organ.
Corticosteroids
(kor
0
tĭ-ko-stĕ
9
roidz) Steroid hormones released by the
adrenal cortex.
Cortisol (hydrocortisone)
(kor
9
tih-sol) Glucocorticoid produced by the
adrenal cortex.
Covalent bond
(ko-va
9
lent) Chemical bond created by electron sharing
between atoms.
Cranial nerves
Te 12 nerve pairs that arise from the brain.
Craniosacral division
Another name for the parasympathetic division
of the autonomic nervous system.
Cranium (cranial bones)
(kra
9
ne-um) Bony protective encasement of
the brain and organs of hearing and equilibrium.
Creatine kinase
(kre
9
ah-tin) Enzyme that catalyzes the transfer of
phosphate from creatine phosphate to ADP, forming creatine and A±P;
important in muscle contraction.
Creatine phosphate (CP)
(fos-fāt) Compound that serves as an alterna-
tive energy source for muscle tissue.
Creatinine
(kre-at
9
ĭ-nin) A nitrogenous waste molecule which is not
reabsorbed by the kidney; this characteristic makes it useful for measure-
ment of the GFR and glomerular function.
Crista ampullaris
Sensory receptor organ for rotational acceleration and
deceleration housed within the ampulla of each semicircular canal of the
inner ear.
Cross section
A cut running horizontally from right to le², dividing the
body or an organ into superior and inferior parts.
Cutaneous
(ku-ta
9
ne-us) Pertaining to the skin.
Cutaneous sensory receptors
Receptors located throughout the skin that
respond to stimuli arising outside the body; part of the nervous system.
Cyclic AMP
Intracellular second messenger that mediates the effects
of the first (extracellular) messenger (hormone or neurotransmitter);
formed from A±P by a plasma membrane enzyme (adenylate cyclase).
Cystic fibrosis (CF)
Genetic disorder in which secretion of overly vis-
cous mucus clogs the respiratory passages, predisposes to fatal respira-
tory infections.
Cytochromes
(si
9
to-krōmz) Brightly colored iron-containing proteins
that form part of the inner mitochondrial membrane and function as
electron carriers in oxidative phosphorylation.
Cytokines
Small proteins that act as chemical messengers between vari-
ous parts of the immune system.
Cytokinesis
(si
0
to-kĭ-ne
9
sis) Te division of cytoplasm that occurs a²er
the cell nucleus has divided.
Cytoplasm
(si
9
to-plazm) Te cellular material surrounding the nucleus
and enclosed by the plasma membrane.
Clonal selection
(klo
9
nul) Process during which a B cell or ± cell be-
comes activated by binding with an antigen.
Clone
Descendants of a single cell.
Coagulation
Process in which blood is transformed from a liquid to a
gel; blood clotting.
Cochlea
(kok
9
le-ah) Snail-shaped chamber of the bony labyrinth that
houses the receptor for hearing [the spiral organ (organ of Corti)].
Codon
(ko
9
don) Te three-base sequence on a messenger RNA molecule
that provides the genetic information used in protein synthesis; code for
a given amino acid.
Coenzyme
(ko-en
9
zīm) Nonprotein substance associated with and acti-
vating an enzyme, typically a vitamin.
Cofactor
Metal ion or organic molecule that is required for enzyme activity.
Collagen fiber
Te most abundant of the three fibers found in the matrix
of connective tissue.
Colloid
(kol
9
oid) (1) A mixture in which the solute particles (usually
proteins) do not settle out readily. (2) Substance in the thyroid gland
containing thyroglobulin protein.
Colloid osmotic pressure
(kol
9
oid ahz-mah
9
tik) Pressure created in
a fluid by large nondiffusible molecules, such as plasma proteins that
are prevented from moving through a (capillary) membrane. Such sub-
stances tend to draw water to them.
Colon
Regions of the large intestine; includes ascending, transverse, de-
scending, and sigmoid portions.
Combination (synthesis) reaction
Chemical reaction in which larger,
more complex atoms or molecules are formed from simpler ones.
Complement
A group of bloodborne proteins, which, when activated,
enhance the inflammatory and immune responses and may lead to cell
lysis.
Complementarity of structure and function
Te relationship between
a structure and its function; i.e., structure determines function.
Complementary base
Refers to how a given nitrogenous base of DNA
or RNA bonds to another nitrogenous base. For example, adenine (A) is
the complementary base of thymine (±). Te result is base pairing.
Complete blood count (CBC)
Clinical test that includes counts of all
formed elements, a hematocrit, and measurements of erythrocyte size
and hemoglobin content.
Compound
Substance composed of two or more different elements, the
atoms of which are chemically united.
Concentration gradient
Te difference in the concentration of a par-
ticular substance between two different areas.
Conducting zone
Includes all respiratory passageways that provide con-
duits for air to reach the sites of gas exchange (the respiratory zone).
Conductivity
Ability to transmit an electrical impulse.
Cones
One of the two types of photoreceptor cells in the retina of the
eye; provide for color vision.
Congenital
(kun-jeh
9
nih-tul) Existing at birth.
Congestive heart failure (CHF)
Condition in which the pumping ef-
ficiency of the heart is depressed so that circulation is inadequate to meet
tissue needs.
Conjunctiva
(kon
0
junk-ti
9
vah) Tin, protective mucous membrane lin-
ing the eyelids and covering the anterior surface of the eye itself.
Connective tissue
A primary tissue; form and function vary extensively.
Functions include support, storage, and protection.
Consciousness
Te ability to perceive, communicate, remember, under-
stand, appreciate, and initiate voluntary movements.
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