Which hormone is secreted by the adrenal medulla and increases in times of stress or excitement?

• A. Epinephrine
• B. Norepinephrine
• C. Cortisol
• D. Aldosterone

Answer: (A)

When the body is stressed or excited, the adrenal medulla releases catecholamines to rapidly prepare the body for action. The principal hormone produced there is epinephrine, often called adrenaline. It quickly raises heart rate and force of contraction, dilates airways, stimulates liver glucose release to boost energy, and redirects blood to muscles. Norepinephrine is also released from the medulla and helps with vascular tone, but epinephrine is the main hormone most closely tied to the fight-or-flight surge. Cortisol and aldosterone come from the adrenal cortex, not the medulla, and have different roles in stress response and electrolyte balance.