Hypothalamus and Anterior Pituitary

The hypothalamus secretes hormones onto the anterior pituitary via a capillary portal system to regulate what hormones the anterior pituitary then secretes. So severing the connection of this portal system will prevent the hypothalamic hormones from stimulating release of anterior pituitary hormones.

A) Epinephrine is a neurohormone secreted by the adrenal medulla in response to nervous stimulation. It is not released in response to pituitary hormones. Thus, there would be NO EFFECT.

B) FSH secretion by the anterior pituitary is stimulated by GnRH (gonagotropin-releasing hormone) from the hypothalamus. So FSH secretion would DECREASE.

C) GH secretion by the anterior pituitary is stimulated by GHRH (growth hormone-releasing hormone) from the hypothalamus. So GH secretion would DECREASE.

D) ADH (or vasopressin) is secreted by the posterior pituitary, which has a different connection with hypothalamus than the anterior pituitary. Thus, there would be NO EFFECT.

E) Aldosterone is secreted by the adrenal cortex in response to ACTH (adrenocorticotropic hormone) from the anterior pituitary, which is stimulated by CRH (corticotropin-releasing hormone) from the hypothalamus. So ACTH secretion would decrease, followed by a DECREASE in aldosterone secretion.

E is wrong! ACTH does NOT stimulate Aldosterone secretion. Aldosterone levels are maintained primarily by potassium levels and by Angiotensin II. There would be no change for Aldosterone.