Dictionary

autograft Tissue transplanted from one part of the body to another in the same individual. Also known as an autotransplant.

autoimmune disorder A condition characterized by autoimmunity in which a misdirected immune system acts against the tissues of one’s own body. Autoimmune disorders typically feature inflammation of various tissues of the body and are associated with antinuclear antibodies (ANAs) in the blood. Examples of autoimmune disorders include systemic lupus erythematosus, Sjogren’s syndrome, rheumatoid arthritis, polymyositis,…

autoimmune hemolytic anemia A condition in which the immune system destroys red blood cells, resulting in fewer of these oxygen-transporting cells. See also hemolytic anemia.

autoimmune thyroiditis See Hashimoto disease.

autoimmunity The state of being attacked by one’s own immune system. Patients whose misdirected immune systems attack their own body tissues are said to have autoimmunity. See also antinuclear antibody; autoimmune disorder.

autologous In blood transfusion and transplantation, a situation in which the donor and recipient are the same person. Patients scheduled for nonemergency surgery may be autologous donors by donating blood for themselves that will be stored until the surgery. An autologous graft is a graft (such as a graft of skin) that is provided for…

automated external defibrillator A device that automatically analyzes the heart rhythm and that— if it detects a problem that may respond to an electrical shock—delivers a shock to restore a normal heart rhythm. Thanks to their small size and ease of use, AEDs have been installed in many settings (such as schools and airports), and…

automatism A behavior that is performed without conscious knowledge and that does not appear to be under conscious control. This curious type of behavior occurs in a number of neurological and psychiatric disorders. The neurologic disorders associated with automatism include narcolepsy and some forms of epilepsy. The psychiatric conditions associated with automatism include schizophrenia and…

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…

autopsy A postmortem examination. Also known as necropsy.

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.

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.