Kaplan Nursing Entrance Exam Practice 2026 – Comprehensive Prep

The adrenal medulla plays a crucial role in the body’s response to stress and is responsible for the secretion of catecholamines, primarily adrenaline (also known as epinephrine). When the body encounters a stressful situation, the adrenal medulla produces adrenaline to help initiate a "fight or flight" response. This hormone increases heart rate, dilates airways, and enhances blood flow to muscles, thus preparing the body to respond quickly and effectively to a perceived threat.

Cortisol, while also associated with stress response, is secreted by the adrenal cortex, not the medulla. Glucagon is produced by the pancreas and plays a role in increasing blood glucose levels. Thyroxine, on the other hand, is a hormone produced by the thyroid gland and is primarily involved in regulating metabolism. Understanding the functions and sources of these hormones clarifies why adrenaline is specifically associated with the adrenal medulla and is vital for managing acute stress responses.