Adrenal medulla

Adrenal Medulla

The adrenal medulla is the inner part of the adrenal gland, a small gland that sits on top of the kidney. It is responsible for the production of certain hormones, most notably epinephrine (also known as adrenaline) and norepinephrine (also known as noradrenaline), which play a crucial role in the body's fight-or-flight response.

Structure

The adrenal medulla is surrounded by the adrenal cortex, the outer part of the adrenal gland. It is composed of chromaffin cells, which are large, irregularly shaped cells that are packed with granules containing epinephrine and norepinephrine.

Function

The primary function of the adrenal medulla is to produce and secrete epinephrine and norepinephrine. These hormones are released into the bloodstream in response to stress or danger, triggering a series of physiological changes that prepare the body for action. This includes increasing heart rate, blood pressure, and blood glucose levels, as well as dilating the airways to improve oxygen supply to the muscles.

Clinical significance

Diseases of the adrenal medulla are relatively rare but can be serious. They include pheochromocytoma, a rare tumor that can cause high blood pressure, and neuroblastoma, a type of cancer that often starts in the adrenal glands and primarily affects children.

See also

• Adrenal gland
• Adrenal cortex
• Epinephrine
• Norepinephrine
• Fight-or-flight response
• Pheochromocytoma
• Neuroblastoma