Aristotle: Aristotle of Stagira (384-322 B.C.), Greek philosopher and scientist. The son of a physician, Aristotle was a student of Plato but developed methods of inquiry different from those of his teacher. Unlike Plato, Aristotle felt that one could, and in fact must, trust one’s senses in the investigation of knowledge and reality.
Aristotle’s writings cover a wide variety of subjects. His treatises on human anatomy are lost, but his many works on animals advocate direct observation and anatomical comparisons between species through dissection. Aristotle set the stage for what would be the scientific method.
Aristotle taught early (now known to be incorrect) concepts that life arises by spontaneous generation, semen is superfluous, the seat of consciousness is in the heart, and disease is due to imbalance between the four humors.
Arm: In popular usage, the appendage that extends from the shoulder to the hand. However, the medical definition refers to the upper extremity extending from the shoulder only to the portion of the elbow, excluding the forearm, which extends from the elbow to the wrist. The arm contains one bone: the humerus.
ARMD: Age-related macular degeneration (which may also be abbreviated as AMD).
- Armed Forces Institute of Pathology
Armed Forces Institute of Pathology: An agency of the US Department of Defense specializing in pathology consultation, education and research. The Armed Forces Institute of Pathology (AFIP) consults on many cases, including difficult, unusual, or rare tumors sent for an expert “second opinion.” The AFIP is located in Washington, DC.
Aromasin: Brand name of exemestane, an oral antiestrogen. Aromasin inhibits the enzyme aromatase in the adrenal glands that produces the estrogens (estradiol and estrone) and thereby lowers their levels. It works by decreasing the amount of estrogen the body makes. This can slow or stop the growth of many types of breast cancer cells that […]
Aromatase: An enzyme involved in the production of estrogen that acts by catalyzing the conversion of testosterone (an androgen) to estradiol (an estrogen). Aromatase is located in estrogen-producing cells in the adrenal glands, ovaries, placenta, testicles, adipose (fat) tissue, and brain. The growth of some breast cancers is promoted by estrogens. For example, the drug […]