Epinephrine and norepinephrine are produced by which region of the adrenal gland?

• A. Adrenal medulla
• B. Adrenal cortex
• C. Pituitary
• D. Thyroid

Answer: (A)

Epinephrine and norepinephrine come from the adrenal medulla, the inner part of the adrenal gland. The medulla acts like a modified sympathetic ganglion and releases these catecholamines into the bloodstream in response to stress, preparing the body for rapid action—think faster heart rate, stronger force of heart contractions, airway dilation, and mobilization of energy stores.

The adrenal cortex, in contrast, produces steroid hormones such as cortisol, aldosterone, and androgens, which regulate metabolism and electrolyte balance over longer timescales. The pituitary gland releases regulating hormones like ACTH but does not produce catecholamines, and the thyroid makes thyroid hormones that set metabolic rate rather than catecholamines.