Which hormone does the adrenal medulla secrete?
a. cortisol
b. melatonin
c. antidiuretic hormone
d. norepinephrine
The correct answer and explanation is:
The correct answer is d. norepinephrine.
The adrenal medulla is the inner part of the adrenal glands, which are located on top of the kidneys. It plays a crucial role in the body’s response to stress by releasing specific hormones. The two primary hormones secreted by the adrenal medulla are epinephrine (also known as adrenaline) and norepinephrine (noradrenaline). These hormones are involved in the “fight or flight” response, helping the body prepare for rapid action in stressful situations.
Norepinephrine is particularly important in increasing alertness, focusing attention, and preparing the body for action. When released, it increases heart rate, blood pressure, and blood flow to muscles, while also dilating the airways in the lungs. It essentially prepares the body for physical exertion. While epinephrine has similar effects, it tends to have a more widespread effect on the body, particularly in terms of stimulating the heart and metabolism.
In contrast to norepinephrine, cortisol is a hormone produced by the adrenal cortex (the outer part of the adrenal glands), not the medulla. Cortisol helps the body manage stress over a longer period by regulating metabolism, immune function, and the body’s inflammatory response. Melatonin, on the other hand, is secreted by the pineal gland and regulates sleep-wake cycles, while antidiuretic hormone (ADH) is produced by the hypothalamus and released by the posterior pituitary to help control water balance in the body.
Therefore, the adrenal medulla primarily secretes norepinephrine, which plays a significant role in short-term stress responses and physiological adaptations.