Appendix A: Glossary of Medical Terms
Adapted from Stedman’s Electronic Medical Dictionary,
Williams & Wilkins, Baltimore, MD, 1996 and
Principles and Practice of Infectious Diseases,
Mandell et al, Third Edition.
Acetylcholine (ACH, Ach) - The neurotransmitter substance at cholinergic synapses, which causes cardiac inhibition, vasodilation, gastrointestinal peristalsis, and other parasympathetic effects. It is liberated from preganglionic and postganglionic endings of parasympathetic fibers and from preganglionic fibers of the sympathetic as a result of nerve injuries, whereupon it acts as a transmitter on the effector organ; it is hydrolyzed into choline and acetic acid by acetylcholinesterase before a second impulse may be transmitted.
Active immunization -The act of artificially stimulating the body to develop antibodies against infectious disease by the administration of vaccines or toxoids.
Adenopathy - Swelling or morbid enlargement of the lymph nodes.
Aleukia - Absence or extremely decreased number of leukocytes in the circulating blood.
Analgesic - 1. A compound capable of producing analgesia, i.e., one that relieves pain by altering perception of nociceptive stimuli without producing anesthesia or loss of consciousness. 2. Characterized by reduced response to painful stimuli.
Anaphylaxis - The term is commonly used to denote the immediate, transient kind of immunologic (allergic) reaction characterized by contraction of smooth muscle and dilation of capillaries due to release of pharmacologically active substances (histamine, bradykinin, serotonin, and slow-reacting substance), classically initiated by the combination of antigen (allergen) with mast cell-fixed, cytophilic antibody (chiefly IgE).
Anticonvulsant - An agent which prevents or arrests seizures.
Antitoxin - An antibody formed in response to and capable of neutralizing a biological poison; an animal serum containing antitoxins.
Arthralgia - Severe pain in a joint, especially one not inflammatory in character.
AST - Abbreviation for aspartate aminotransferase, a liver enzyme.
Asthenia - Weakness or debility.
Ataxia - An inability to coordinate muscle activity during voluntary movement, so that smooth movements occur. Most often due to disorders of the cerebellum or the posterior columns of the spinal cord; may involve the limbs, head, or trunk.