Adrenalin

Part of speech: noun

Definitions

1. A hormone produced by the adrenal glands that triggers the body's fight-or-flight reaction to stress or danger
2. A chemical released into the bloodstream during stressful situations that increases heart rate and energy
3. A hormone secreted to prepare the body for rapid action in emergencies by elevating alertness and physical readiness

Etymology: The hormone takes its name from its position in the body. The adrenal glands sit atop the kidneys, and their name combines Latin "ad", meaning "at" or "near", with "renes", meaning "kidneys". The substance was first isolated from that tissue. The Japanese chemist Jokichi Takamine, working in the United States, isolated the hormone in crystalline form and sold it under the trade name Adrenalin. That brand name became the everyday term in many languages. The scientific name, "epinephrine", uses Greek roots: "epi" meaning "upon" and "nephros" meaning "kidney", describing the same location. The spelling with a final "e" is the usual British form.

Synonyms: epinephrine