Correct Response: C. The "fight or flight" response to a stressor begins when the adrenal glands are stimulated to secrete the catecholamines, epinephrine and norepinephrine. These hormones stimulate the necessary physical responses to either fight the perceived harm or to run away from it for the purpose of survival. The hormones triiodothyronine and thyroxine produced by the thyroid (A) are used for regulating metabolism and are not involved directly in the "fight or flight" response. The pituitary gland releases adrenocorticotrophic hormone (B), which causes the release of other hormones to help deal with stress and low blood sugar, but it does not cause the "fight or flight" response. The hormone cortisol released by the parathyroid (D) is produced to deal with long-term stress by maintaining homeostasis; it does not cause the "fight or flight" response.
