Which region of the adrenal gland produces epinephrine and norepinephrine?

The adrenal medulla is the region of the adrenal gland responsible for the production of epinephrine (also known as adrenaline) and norepinephrine (noradrenaline). These hormones are critical components of the body's fight-or-flight response, which prepares the body to respond to stress or danger.

The adrenal medulla is made up of chromaffin cells, which are specialized cells that synthesize and secrete these catecholamines directly into the bloodstream. Upon stimulation by the sympathetic nervous system, the adrenal medulla releases these hormones, leading to effects such as increased heart rate, enhanced breakdown of glycogen to glucose, and improved blood flow to muscles.

In contrast, the adrenal cortex, which includes zones like the zona fasciculata and zona glomerulosa, produces different hormones such as cortisol and aldosterone. These hormones are involved in metabolism, the immune response, and maintaining blood pressure, but they do not produce epinephrine or norepinephrine, which are solely produced in the adrenal medulla. Therefore, the adrenal medulla specifically serves this unique role in the synthesis and secretion of these critical hormones.