Evolve Endocrine Practice Test

The hormone released from the adrenal medulla in response to stress is epinephrine. The adrenal medulla, which is the innermost part of the adrenal glands, plays a crucial role in the body’s response to acute stress through the release of catecholamines. When the body perceives a stressful situation, the sympathetic nervous system is activated, prompting the adrenal medulla to secrete epinephrine, also known as adrenaline.

Epinephrine serves several functions during the stress response – it increases heart rate, dilates air passages, enhances blood flow to muscles, and boosts energy production. These physiological changes prepare the body to respond to a perceived threat, often referred to as the "fight or flight" response.

In contrast, cortisol, which is released from the adrenal cortex, is associated with longer-term stress responses and helps mobilize energy reserves. Insulin, produced by the pancreas, primarily regulates blood glucose levels rather than playing a direct role in acute stress responses. Thyroxine, produced by the thyroid gland, is involved in metabolism but is not directly associated with the immediate stress response.

Thus, epinephrine is the key hormone for the rapid physiological changes needed during acute stress, aligning perfectly with the body’s need for