A hormonal stimulator of the sympathetic nervous system. It acts to constrict peripheral blood flow, raise blood pressure, increase cardiac activity, promote metabolic activity through the release of glucose, and inhibit digestive processes. Epinephrine is considered a psychogenic hormone because it alters psychological processes when released in large quantities, such as under stress. It is produced in the adrenal medulla, located immediately above each kidney. Called adrenaline in British reports.