The BUD/S instructors had a fast way of testing our fight-or-flight response.
fight-or-flight reaction n.
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. Also called emergency theory.
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.