Analytical sensitivity The smallest quantity or concentra-
tion of ananalytethat can be detected by an analyti-
cal method. Compare withanalytical specificity.Analytical specificity The ability of an analytical method
to detect only theanalytein question. Compare with
analytical sensitivity.Anemia A reduced amount of hemoglobin in the blood
because of insufficient red cells or insufficient hemo-
globin in the cells.Aneuploidy A situation in which the number of chromo-
somes is fewer or greater than an exact multiple of the
haploidnumber (seeeuploidyandpolyploidy).Aneurysm A bulge that usually develops in weak areas of
an arterial wall.Anosmia Loss of the sense of smell.Anoxia The absence of oxygen.Antibiotics Drugs used to treat bacterial and other infec-
tious diseases, but which do not affect viruses. Most
antibiotics are derived from microorganisms.Antibodies Glycoproteins produced by the immune sys-
tem that bind toantigens(seeimmunoglobulins).Antigen A macromolecule (protein, lipopolysaccharide)
that provokes an immune response and binds specifi-
cally to anantibody.Antigen presenting cells (APC) White blood cells that
take up animmunogenand process it to form a pep-
tide that can be recognized by THcells resulting in its
activation.Antinuclear factors Antibodiesagainst nuclear compo-
nents that occur in someautoimmuneconditions
such as rheumatoid arthritis and systemic lupus ery-
thematosus (seeextractable nuclear antigens).Anuria Failure to pass urine (compare witholiguria).Apheresis Isolation and concentration of components of
the blood for clinical use (seeplasmapheresis).Apoptosis (programmed cell death) This is also called cell
suicide. A genetically programmed release of enzymes
and other proteins that eventually bring about the
death of a cell.Arrhythmias Disturbances to the heart’s rhythmic
contractions.Arteriosclerosis Seeatherosclerosis.Ascites An abnormal accumulation of fluid (“ascites
fluid”) in the abdomen.Aspergilloma An infective mass of the fungusAspergillus
fumigatusgrowing within an old wound within the
lungs.Ataxia Inability to control muscular movements.Atheroma A hard yellow plaque consisting of a necrotic
(dead) core, rich in cholesterol and surrounded by
fibrous tissue that gradually builds up on the inside of
medium-sized arteries (seeatherosclerosis).Atherosclerosis or arteriosclerosis The simultaneous
development of anatheromain an artery wall and its
sclerosis (abnormal hardening or fibrosis).Atrioventricular or AV node The node situated between
theatriaand theventriclesof the heart which delays
the transmission of impulses from thesinoatrial node
to allow the atria to contract completely and the ven-
tricles to fill with as much blood as possible before
systoleoccurs.Atrium (plural atria) The upper chamber(s) of the heart
(seeventricle).Autoimmune disease A situation in which the immune
system mounts an immune response against“self ”
tissues.Autologous stem cell transplants Use of the patient’s
own stem cells, which were harvested and stored prior
to a treatment, for example by radiation or high-dose
chemotherapy that destroys the patient’s own stem
cells (see also allogeneicand syngeneic).Autosomes The non-sex chromosomes that comprise 22
homologous pairs of the 46 chromosomes found in
humandiploidcells.B lymphocytes Small lymphocytesthat develop fully in
the bone marrow. On stimulation by an immunogen
they develop into antibody producing cells.Bactericidal An antibiotic or other drug that kills its target
bacteria.Bacteriostatic An antibiotic or other drug that prevents
its target bacteria replicating.Balanced diet A diet that supplies adequate energy dis-
tributed appropriately between carbohydrates, lipids,
and proteins along with the necessary amounts of
vitamins, minerals, trace elements, water and non-
digestable fiber.Basophil One of the three types ofpolymorphonuclear
leukocyte(seeeosinophilandneutrophil).Biopsy The removal of a piece of tissue from a patient for
clinical analysis.Black Death Thepandemicof bubonic plague that spread
across Asia and Europe in medieval times. So called
because of the black spots (buboes) that occurred on
the skin of patients.GLOSSARYmm W^dad\nd[Y^hZVhZ