Bleeding time The period of time following wounding
before the flow of blood stops (compare withclotting
time).
Body mass index (BMI) The generally accepted way to
assess the weight of a patient, where BMI = weight
(kg)/height (m)^2 (see alsoideal body weight).
Bone resorption The release of Ca2+from bone.
Bradycardia An abnormally low heart rate.
Broad-spectrum antibiotics Antibiotics that are effective
against Gram-positive and Gram-negative bacteria.
Bronchiectasis A condition in which the bronchi and
bronchioles are abnormally dilated.
Brush border The microscopic extensions called microvilli
on the apical surfaces (i.e. luminal sides) of the plasma
membranes of enterocytes lining the intestine.
Bundle of His A group of modified cardiac muscle fibers,
calledPurkinje fibersthat carry electrical impulses in
the heart.
C3 convertase A proteolytic enzyme consisting of activated
complement proteins C4b2a that cleaves complement
protein C3 into two fragments: C3 and the larger C3b
molecule that is an opsonin.Seeopsonization.
C5 convertase A proteolytic enzyme consisting of com-
plement proteins C3b and C3 convertase involved in
the formation of theMembrane Attack Complex.
Cachexia Severe and prolonged muscle wastage (weight
loss) associated with a number of clinical conditions
including cancer.
Cancer A general term covering a number of diseases
in which the growth of certain body cells becomes
uncontrolled forming a tumor, which may be benign
ormalignant.
Capsid The complex of proteins that forms a shell enclos-
ing the nucleic acid of a virus.
Carbuncle An amalgam of several abcesses or boils.
Carcinogens Environmental agents (compounds, radia-
tion) that cause cancers.
Carditis General inflammation of the heart.
Carriers (asymptomatic) Individuals who harbor a path-
ogen but aresymptom free.
Cell cycle This is an orderly sequence of biochemical
and morphological events that constitute the growth
phases of a reproducing cell.Seeinterphase,mitosis
andmeiosis.
Cell-mediated immunity (CMI) Production of cells that
kill or recruit other cells to kill host cells that are
infected by viruses or other intracellular parasitic
microorganisms (compare withhumoral immunity).Cerebrovascular accident Seestroke.Chemotactic The ability of substances secreted by cells to
attract other cells to the area.Chloride shift The exchange of HCO 3 – for Cl–across the
membrane of the erythrocyte.Cholelithiasis The formation of gallstones.Cholestasis The failure of bile to reach the small
intestine.Chromatid One of the pair constituting a condensed rep-
licated chromosome present atmitosisormeiosis.Chronic Diseases or clinical events that develop gradually
over a relatively long time and persist (compare with
acute).Chronic rejection of a transplantation Immunological
rejection that occurs over months or years by a com-
bination ofcell-mediatedandhumoral immunity.Chylomicron Large lipoprotein complexes that transport
triacylglycerols, phospholipids and lipid-soluble vita-
mins from the gastrointestinal tract to the lacteals of
the lymphatic system.Chyme The watery mixture of gastric juice and partially
digested food released from the stomach into the
small intestine.Classical pathway of complement activation The path-
way initiated when certain classes ofantibodybinds to
animmunogen(compare withalternative pathway).Clinical audit A process whereby practices and proce-
dures involved in patient care are monitored and, if
necessary, revised to provide a more effective, efficient
and cost-effective service.Clinical biochemistry The science concerned with inves-
tigating the biochemical changes associated with
diseases.Clinical genetics The science concerned with the identifi-
cation of genetic abnormalities.Clinical manifestations of disease These include the
signsandsymptomsassociated with the disease.Clotting time The period required to seal a wound with
a clot that prevents further blood loss (usually 6 to 12
minutes). Compare withbleeding time.Codons These are the three bases in a nucleic acid each
of which code for a single amino acid residue in a
polypeptide.GLOSSARYCZhhVg6]bZY!BVjgZZc9Vlhdc!8]g^hHb^i]:YLddY mm^