Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «A»:
Achromatopsia: An hereditary disorder of sight due to a lack of cone vision - that type of vision provided by the cone photoreceptors in the retina. In the normal eye, there are some 6 million cone photoreceptors; they are located largely in the center of the retina. Lacking cones, persons with achr...
Achromycin: See: Tetracycline....
Acid deposition: A complex chemical and atmospheric phenomenon that occurs when emissions of sulfur and nitrogen compounds and other substances are transformed by chemical processes in the atmosphere and then deposited on earth in either wet or dry form. The wet forms, popularly called acid rain, ca...
Acid indigestion: Excessive secretion of hydrochloric acid by the stomach cells. Medically known as hyperchlorhydria. Sometimes used interchangeably with heartburn. See also: Heartburn....
Acid phosphatase: Acid phosphatase is an enzyme that works under acid conditions and is made in the liver, spleen, bone marrow and the prostate gland.
Abnormally high serum levels of the enzyme may, for example, indicate prostate disease (infection, injury, or cancer)....
Acid rain: Rain resulting from the combination of fossil fuel emissions and water in the atmosphere. The environmental effects of acid rain include the acidification of lakes and streams, damage to trees at high altitude, the acceleration of decay in buildings and poorer air quality.
Acid rain also...
Acid reflux: A common condition and an abnormal one in which acid in the stomach rises up into the esophagus. This occurs because the valve separating the contents of the stomach from the esophagus does not function properly. See also: GERD....
Acid, amino: One of the 20 building blocks of protein. The sequence of amino acids in a protein and, hence, the function of that protein are determined by the genetic code in the DNA.
Amino acids are molecules that (in technical terms) contain a basic amino (NH2) group, an acidic carboxyl (COOH) gro...
Acid, bile: See: Bile acid....
Acid, fatty: One of many molecules that are long chains of lipid-carboxylic acid found in fats and oils and in cell membranes as a component of phospholipids and glycolipids. (Carboxylic acid is an organic acid containing the functional group -COOH.)
Fatty acids come from animal and vegetable fats...
Acid, folic: One of the B vitamins that is a key
factor in the synthesis (the making) of nucleic acid (DNA and RNA).
A deficiency of folic acid after birth causes a kind of anemia, namely, megaloblastic anemia in which there is a paucity of red blood cells and those that are made are unusually lar...
Acid, nucleic: One of the molecules in the chromosomes of living cells and viruses that plays a central role in the storage and replication of hereditary information and in the expression of this information through protein synthesis. The two chief types of nucleic acids are:
Acid, pantothenic : Pantothenic acid is vitamin B5, one of the less well known B vitamins, perhaps because it is widely distributed in nature.
Pantothenic acid is virtually ubiquitous. It is present in foods as diverse as poultry, soybeans, yogurt, and sweet potatoes.
No naturally occurring disease ...
Acid, trans fatty
Acid, trans fatty: An unhealthy substance, also known as trans fat, made through the chemical process of hydrogenation of oils. Hydrogenation solidifies liquid oils and increases the shelf life and the flavor stability of oils and foods that contain them. Trans fat is found in vegetable shortenings ...
Acid-base balance: Acid-base balance refers to the mechanisms the body uses to keep its fluids close to neutral pH (that is, neither basic nor acidic) so that the body can function normally....