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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.
fight-or-flight responseFlight-or-fight response, general adaptation syndrome, stress response Physiology A constellation of physiologic responses to fear or perceived stress imminent danger or anticipated pain, which triggers full-scale CNS activation and release of 'stressors' by adrenal medulla–eg epinephrine and norepinephrine and cortex–eg corticosteroids, mineralocorticoids, kidneys–renin, pancreas–insulin Clinical Tachycardia, ↑ blood flow to muscle, ↑ BP, muscle tone, ↑ O2 consumption, sweating, ↑ respiratory rate, tremor, pallor, ↑ inotropism, vasoconstriction, mydriasis, bronchodilation, hyperglycemia. Cf Relaxation response.
n the psychophysiologic response to a perceived threat that prepares the organism for action.