- the response of the sympathetic nervous system to a stressful event, preparing the body to fight or flee, associated with the adrenal secretion of epinephrine and characterized by increased heart rate, increased blood flow to the brain and muscles, raised sugar levels, sweaty palms and soles, dilated pupils, and erect hairs.
Also called fight-or-flight response.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- A set of physiological changes, such as increases in heart rate, arterial blood pressure, and blood glucose, initiated by the sympathetic nervous system to mobilize body systems in response to stress.emergency theory
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- A physiological reaction in response to stress, characterized by an increase in heart rate and blood pressure, elevation of glucose levels in the blood, and redistribution of blood from the digestive tract to the muscles. These changes are caused by activation of the sympathetic nervous system by epinephrine (adrenaline), which prepares the body to challenge or flee from a perceived threat.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.