Definition

1. Noun:
   • A hormone and neurotransmitter: Epinephrin is a catecholamine hormone and neurotransmitter secreted primarily by the adrenal medulla. It is a key component of the body's "fight-or-flight" response to stress, danger, or excitement.
   • A physiological stimulant: It acts on various organs to prepare the body for rapid action, increasing heart rate, blood pressure, and blood flow to muscles.

Usage Examples

• Noun:
  • The doctor administered a shot of epinephrin to counteract the severe allergic reaction.
  • During the emergency, her body released large amounts of epinephrin, heightening her senses and strength.

Advanced Usage

• "Epinephrin surge/rush": A sudden, large release of the hormone.
  • He felt an epinephrin rush as he stepped onto the stage to give his speech.
• "Epinephrin auto-injector": A medical device (like an EpiPen) designed for self-administration of the hormone in emergency situations.
  • People with severe allergies should always carry an epinephrin auto-injector.

Variants and Related Words

• Epinephrine (n): The more common international nonproprietary name (INN) for the same substance. "Epinephrin" and "epinephrine" are used interchangeably.
• Adrenaline (n): The British English and common trade name for epinephrin. This term is widely used in informal contexts.
  • The thrill-seeker was addicted to the adrenaline rush.

Synonyms

• Adrenaline: The common synonym, especially outside of formal medical contexts.
• Catecholamine: A class of molecules to which epinephrin belongs, though this is a broader category.

Related Phrases

• "Fight-or-flight response": The physiological reaction triggered by the release of epinephrin and other hormones.
  • The loud noise triggered his fight-or-flight response, flooding his system with epinephrin.

Noun

1. a catecholamine secreted by the adrenal medulla in response to stress (trade name Adrenalin); stimulates autonomic nerve action