Dictionary

AVM Arteriovenous malformation. See malformation, arteriovenous.

avian influenza A highly contagious viral disease with up to 100 percent mortality in domestic fowl. Caused by influenza A virus subtypes H5 and H7. All types of birds are susceptible to the virus, but outbreaks occur most often in chickens and turkeys. The infection may be brought by migratory wild birds which can carry…

avascular necrosis A condition in which poor blood supply to an area of bone leads to bone death. Abbreviated AVN. Also known as aseptic necrosis and osteonecrosis.

AV node Atrioventricular node.

AV 1 Atrioventricular. Relating to the atrium(atria) and ventricle(s) of the heart. 2 Arteriovenous. Relating to an artery(ies) and a vein(s).

aux Prefix indicating growth or increase.

autosome Any chromosome other than the X and Y sex chromosomes. People normally have 22 pairs of autosomes (44 autosomes) in each cell.

autosomal recessive trait A genetic trait that appears only in patients who have received two copies of a specific autosomal (nonsex) gene for that particular trait, one from each parent. For example, sickle cell anemia and cystic fibrosis are autosomal recessive traits.

autosomal dominant trait A genetic trait that appears in patients who have received one copy of a specific autosomal (nonsex) gene for that particular trait. For example, achondroplasia, Marfan syndrome, and Huntington disease are autosomal dominant traits.

autosomal Pertaining to a chromosome that is not a sex chromosome. People normally have 22 pairs of autosomes (44 autosomes) in each cell, together with 2 sex chromosomes, X and Y in a male and X and X in a female.

autopsy A postmortem examination. Also known as necropsy.

autonomic nervous system A part of the nervous system that regulates key involuntary functions of the body, including the activity of the heart muscle; the smooth muscles, including the muscles of the intestinal tract; and the glands. The autonomic nervous system has two divisions: the sympathetic nervous system, which accelerates the heart rate, constricts blood…