In the human body, which gland secretes growth hormone?

• A. Adrenal gland
• B. Thyroid gland
• C. Pineal gland
• D. Pituitary gland

Answer: (D)

Growth hormone is produced by the pituitary gland, specifically by its anterior lobe. The hypothalamus regulates its release with growth hormone–releasing hormone to stimulate secretion and somatostatin to inhibit it. Once released, growth hormone acts on many tissues and also stimulates the liver to produce IGF-1, which drives growth of bones and tissues in children and supports metabolism and muscle maintenance in adults. The other glands listed do not secrete growth hormone: the adrenal gland makes cortisol and other hormones, the thyroid gland produces thyroid hormones, and the pineal gland secretes melatonin.