Dictionary

adrenal medulla See medulla, adrenal.

adrenaline A stress hormone produced within the adrenal gland that quickens the heart beat, strengthens the force of the heart’s contraction, and opens up the bronchioles in the lungs, among other effects. The secretion of adrenaline is part of the human “fight or flight” response to fear, panic, or perceived threat. Also known as epinephrine.

adult hemoglobin See hemoglobin A.

adult-onset diabetes Non-insulin-dependent, or type 2, diabetes, the most common form of diabetes mellitus. Unlike patients with insulin-dependent, or type 1, diabetes, in whom the pancreas makes no insulin, patients with adult-onset diabetes produce some insulin, sometimes even large amounts. However, their bodies do not produce enough insulin or their body cells are resistant to…

adult-onset Still’s disease Still’s disease that begins in adulthood rather than in childhood. See also Still’s disease.

advance directive A document drawn up by a patient or, in some cases, the patient’s representative to set treatment preferences and to designate a surrogate decision maker should the patient become unable to make medical decisions. Advance directives include the living will, power of attorney, and health care proxy. See also DNR.

adverse event In pharmacology, any unexpected or dangerous reaction to a drug or vaccine.

AED See automated external defibrillator.

aer-, aero- Prefix indicating air or gas, such as aerogastria (excess stomach gas).

aerobic Oxygen-requiring. Aerobic bacteria need oxygen to grow. Aerobic exercise requires the heart and lungs to work harder to meet the body’s increased oxygen demand.

aerobic exercise Brisk exercise that promotes the circulation of oxygen through the blood and is associated with an increased rate of breathing. Examples include running, swimming, and bicycling.

aerophagia Literally, eating air, from the Greek words aer, meaning “air,” and phagein, meaning “to eat.” Aerophagia is a common cause of stomach gas. Everyone swallows small amounts of air when eating or drinking. However, activities such as rapid eating or drinking, gum chewing, smoking, and wearing ill-fitting dentures may cause a significant increase in…