Aldosterone: A hormone produced by the outer portion (cortex) of the adrenal gland. Aldosterone regulates the balance of water and electrolytes in the body, encouraging the kidney to excrete potassium into the urine and retain sodium, thereby retaining water. It is classified as a mineralocorticoid hormone.
Aldosteronism: Overproduction of the hormone aldosterone from the cortex (the outer layer) of the adrenal gland or a tumor containing that type of tissue. Excess aldosterone (pronounced al’-do-ster-one) results in low potassium levels (hypokalemia), underacidity of the body (alkalosis), muscle weakness, excess thirst (polydipsia), excess urination (polyuria), and high blood pressure (hypertension). Also called hyperaldosteronism […]
Alembic: A type of still, an apparatus used in the process of distillation. Alembics were employed in chemistry and biomedical laboratories as well as in distilling cognac. By extension, “alembic” is anything that refines or transmutes as if by distillation. For example, the alembic of the surgeon’s mind. From the Arabic al-anbiq meaning “the still” […]
- Alexander disease
Alexander disease: A slowly progressive and ultimately fatal brain disorder that most commonly occurs in children. The infantile form of the disease is characterized by megalencephaly (an abnormally large head), seizures, spasticity and developmental retardation. It leads to death usually within the first decade. Patients with the juvenile and adult forms of Alexander disease typically […]
- Alexander technique
Alexander technique: A process that teaches how to properly coordinate body and mind to release harmful tension and to improve posture, coordination and general health. The technique is named for the Australian Frederick Matthias Alexander (1869-1955) who developed it. An actor, Alexander began his career as a Shakespearean orator. He developed chronic laryngitis while performing. […]
Alexia: Loss of the ability to read or understand the written word, due either to brain damage that disconnects these functions or to temporary dysfunction caused by abnormal electrical or chemical activity in the brain.