Apraxia: The inability to execute a voluntary motor movement despite being able to demonstrate normal muscle function. Apraxia is not related to a lack of understanding or to any kind of physical paralysis; rather, it is caused by a problem in the cortex of the brain.
- Apraxia of speech
Apraxia of speech: A severe speech disorder characterized by inability to speak, or a severe struggle to speak clearly. Apraxia of speech occurs when the oral- motor muscles do not or cannot obey commands from the brain, or when the brain cannot reliably send those commands. Children with apraxia can be helped significantly with intensive […]
- APS (autoimmune polyglandular syndrome)
APS (autoimmune polyglandular syndrome): A genetic autoimmune disease with an extraordinary array of clinical features but characterized most often by at least 2 of the following 3 findings: hypoparathyroidism — underfunction of the parathyroid glands which control calcium, candidiasis (yeast infection), and adrenal insufficiency (underfunction of the adrenal gland). APS was the first systemic (bodywide) […]
Aorta: The largest artery in the body, the aorta arises from the left ventricle of the heart, goes up (ascends) a little ways, bends over (arches), then goes down (descends) through the chest and through the abdomen to where ends by dividing into two arteries called the common iliac arteries that go to the legs. […]
AOA: Abbreviation for Alpha Omega Alpha, the medical honor society, the medical school equivalent of Phi Beta Kappa, in the United States and Canada. Membership is by election for distinguished academic achievement. Medical students, house officers, and medical school alumni and faculty are eligible for election. AOA is also the abbreviation for the American Osteopathic […]
- Aqueduct of Sylvius
Aqueduct of Sylvius: A canal between the third and fourth ventricles in the brain within the system of four communicating cavities that are continuous with the central canal of the spinal cord. The ventricles are filled with cerebrospinal fluid, which is carried by the aqueduct of Sylvius.