Which gland secretes adrenaline?

The gland that secretes adrenaline is the adrenal medulla. This part of the adrenal glands, which are located on top of the kidneys, is responsible for the production and release of catecholamines, including adrenaline (also known as epinephrine). Adrenaline plays a crucial role in the body's "fight or flight" response, increasing heart rate, blood flow to muscles, and energy availability to prepare the body for quick reactions in response to stress or danger.

The adrenal medulla's secretion of adrenaline is regulated by the sympathetic nervous system, which activates during times of stress. This release of adrenaline leads to various physiological changes that enhance the body's ability to react to acute stressors.

In contrast, the thyroid gland primarily produces thyroid hormones that regulate metabolism, growth, and development. The pituitary gland, often referred to as the "master gland," secretes several hormones that control various endocrine functions but does not produce adrenaline. The pancreas mainly functions in digestion and blood glucose regulation through the secretion of insulin and glucagon. Understanding these different roles helps clarify why the correct answer is indeed the adrenal medulla.