Which hormone is secreted by the hypothalamus to stimulate the pituitary gland to release ACTH?

Which hormone is secreted by the hypothalamus to stimulate the pituitary gland to release ACTH?

• A. Growth hormone
• B. Follicle-stimulating hormone
• C. Prolactin-inhibiting hormone
• D. Corticotropin-releasing hormone

Answer: (D)

Understanding how the hypothalamus controls ACTH release through releasing hormones. The hypothalamus sends corticotropin-releasing hormone into the portal circulation to the anterior pituitary, where it stimulates corticotroph cells to secrete adrenocorticotropic hormone (ACTH). ACTH then acts on the adrenal cortex to produce cortisol, and cortisol provides negative feedback to dampen further CRH and ACTH release. Among the options, corticotropin-releasing hormone is the specific signal from the hypothalamus that triggers ACTH release. The other hormones listed are involved in different axes: growth hormone is regulated by hypothalamic GHRH and somatostatin; FSH is controlled by gonadotropin-releasing hormone; prolactin-inhibiting hormone (dopamine) primarily suppresses prolactin release rather than ACTH.

Understanding how the hypothalamus controls ACTH release through releasing hormones. The hypothalamus sends corticotropin-releasing hormone into the portal circulation to the anterior pituitary, where it stimulates corticotroph cells to secrete adrenocorticotropic hormone (ACTH). ACTH then acts on the adrenal cortex to produce cortisol, and cortisol provides negative feedback to dampen further CRH and ACTH release. Among the options, corticotropin-releasing hormone is the specific signal from the hypothalamus that triggers ACTH release. The other hormones listed are involved in different axes: growth hormone is regulated by hypothalamic GHRH and somatostatin; FSH is controlled by gonadotropin-releasing hormone; prolactin-inhibiting hormone (dopamine) primarily suppresses prolactin release rather than ACTH.