Archaeology: The scientific study of the material remains of past peoples. In archaeology today, a range of biological techniques, including DNA analysis, enter into what has been termed bioarchaeology.
- Arcuate neuron
Arcuate neuron: A neuron in the arcuate nucleus of the brain. See: Arcuate nucleus.
- Arcuate nucleus
Arcuate nucleus: A collection of neurons (nerve cells) in the hypothalamus of the brain. Some arcuate neurons contain dopamine and act to inhibit the release of the hormone prolactin by the pituitary gland. Other arcuate neurons contain a substance called neuropeptide Y (NPY) and influence hunger. When activated, these neurons can produce remarkable increases in […]
- Arcus senilis
Arcus senilis: A cloudy opaque arc or circle around the edge of the eye, often seen in the eyes of the elderly.
Acronym that stands for a disorder known as or Acute Respiratory Distress Syndrome. In ARDS there is respiratory failure of sudden (acute) onset due to the rapid accumulation of fluid in the lungs (pulmonary edema) following an abrupt increase in the permeability of the normal barrier between the capillaries and the air sacs in the […]
Areflexia: Absence of neurologic reflexes such as the knee jerk reaction.