What hormone is released by the adrenal medulla during stress?

The hormone released by the adrenal medulla during stress is adrenaline, also known as epinephrine. This hormone plays a crucial role in the body's "fight or flight" response, which prepares the body to respond to a perceived threat. When a person experiences stress, the adrenal medulla releases adrenaline into the bloodstream, resulting in a series of physiological changes. These changes include increased heart rate, elevated blood pressure, and enhanced energy availability, all designed to prepare the body for rapid physical action.

Adrenaline acts quickly, affecting various systems in the body, such as increasing oxygen supply to muscles and improving the efficiency of energy use. This response is vital for survival, enabling individuals to either confront danger or escape from it efficiently.

Other hormones, such as cortisol, are involved in the stress response but are released by the adrenal cortex rather than the adrenal medulla. Norepinephrine, while also related to stress responses, is primarily involved in maintaining blood pressure and is less prominent in the acute stress response compared to adrenaline. Testosterone, on the other hand, is a steroid hormone associated primarily with sexual development and does not have a direct role in the immediate stress response.