Glossary
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Chemosis
Excessive edema of the mucous membrane
of the eyeball and eyelid lining (conjunctiva).
Chemotaxis
A response involving cell orientation or
cell movement that is either toward (positive chemo-
taxis) or away from (negative chemotaxis) a chemical
stimulus.
Chimeric
Relating to, derived from, or being an indi-
vidual possessing one’s own immunologic character-
istics and that of another individual; a phenomenon
that can occur as the result of procedures such as a
bone marrow graft.
Chondrocyte
Any one of the mature polymorphic cells
that form the cartilage of the body.
Chromatid
One of the paired threadlike chromosome
filaments, joined at the centromere, that make up a
metaphase chromosome.
Chromosome
Any one of the structures in the nucleus
of a cell containing a linear thread of DNA,
which functions in the transmission of genetic
information.
Chyme
The creamy, viscous, semifluid material pro-
duced during digestion of a meal that is expelled by
the stomach into the duodenum.
Cilia
A minute, hairlike process projecting from a cell,
composed of nine microtubules arrayed around a
single pair. Cilia beat rhythmically to move the cell
around in its environment, or they move mucus or
fluids over the surface.
Circadian
Being, having, pertaining to, or occurring in
a period or cycle of approximately 24 hours.
Circumduction
The active or passive circular move-
ment of a limb or of the eye.
Cisterna
An enclosed space, such as a cavity, that
serves as a reservoir for lymph or other body
fluids.
Clathrin
The major structural coat protein of the
coated vesicles involved in the intracellular transport
between membranous organelles.
Clone
One or a group of genetically identical cells or
organisms derived from a single parent.
Coagulation
The process of transforming a liquid into
a semisolid mass, especially of blood clot formation.
Coarctation
A condition of stricture or contraction of
the walls of a vessel.
Cofactor
A substance that must unite with another
substance in order to function.
Colic
Sharp, intermittent abdominal pain localized in
a hollow or tubular organ, resulting from torsion,
obstruction, or smooth muscle spasm. (Adjective:
colicky)
Collagen
The protein substance of the white, glistening,
inelastic fibers of the skin, tendons, bone, cartilage,
and all other connective tissue.
Collateral
Secondary or accessory rather than direct or
immediate; or a small branch, as of a blood vessel or
nerve.
Complement
Any one of the complex, enzymatic
serum proteins that are involved in physiologic
reactions, including antigen–antibody reaction and
anaphylaxis.
Confluent
Flowing or coming together; not discrete.
Congenital
Present at, and usually before, birth.
Conjugate
To pair and fuse in conjugation; or a form
of sexual reproduction seen in unicellular organisms
in which genetic material is exchanged during the
temporary fusion of two cells.
Contiguous
In contact (or nearly so) in an unbroken
sequence along a boundary or at a point.
Contralateral
Affecting, pertaining to, or originating in
the opposite side of a point or reference.
Contusion
An injury of a part without a break in the
skin, characterized by swelling, discoloration, and
pain.
Convolution
An elevation or tortuous winding, such
as one of the irregular ridges on the surface of the
brain, formed by a structure being folded in upon
itself.
Corpuscle
Any small mass, cell, or body, such as a red
or white blood cell.
Costal
Pertaining to a rib or ribs.
Crepitus
A sound or sensation that resembles a crackling
or grating noise.
Cutaneous
Pertaining to the skin.
Cyanosis
A bluish discoloration, especially of the skin
and mucous membranes, caused by an excess of
deoxygenated hemoglobin in the blood.
Cytokine
Any of a class of polypeptide immunoregula-
tory substances that are secreted by cells, usually of
the immune system, that affect other cells.
Cytology
The study of cells, including their origin,
structure, function, and pathology.
Cytosol
Cytoplasm exclusive of membranous compo-
nents (e.g., mitochondria, endoplasmic reticulum)
and nonmembranous insoluble components.
Decibel
A unit for expressing the relative power sound
intensity that is equal to one tenth of a bel.
Defecation
The evacuation of feces from the digestive
tract through the rectum.
Deformation
The process of adapting in form or shape;
also, the product of such alteration.
Degeneration
The deterioration of a normal cell, tissue,
or organ to a less functionally active form. (Adjective:
degenerative)
Deglutition
The act or process of swallowing.
Degradation
The reduction of a chemical compound
to a compound-less complex, usually by splitting off
one or more groups.
Dehydration
The condition that results from excessive
loss of water from the body tissues.
Delirium
An acute, reversible organic mental syndrome
characterized by confusion, disorientation, restless-
ness, incoherence, fear, and often illusions.
Dendrite
One of the branching processes that extends
and transmits impulses toward a cell body of a
neuron. (Adjective: dendritic)
De novo
Anew; often applied to the biochemical
pathway where a complex biomolecule is
synthesized in a new or different form from simple
molecules.
Depolarization
The reduction of a cell membrane
potential to a less-negative value than that of the
potential outside the cell.
