A 10 - year - old with precocious puberty is found to have a space - occupying tumor in the arcuate nucleus of the hypothalamus, leading to excessive prolactin release. Which of the following correctly describes changes in plasma levels of hormones?

Answer: Increased PRH, decreased PIH, and increased prolactin

Explanation:

The hypothalamus is a part of the brain which links the nervous system to the endocrine system via the pituitary gland.

The hypothalamus secretes pro hormones that act on the pituitary gland to produce other hormones, which in turn act in different tissues or organs of the body to perform different functions. Examples of the functions of these hormones are blood pressure control, temperature regulation, growth, metabolism, among others.

In this example, the person has a tumor located in the hypothalamus. This affects the function of the pituitary gland. In this particular case, the gland secretes large amounts of prolactin irregularly. This would increase the levels of PRH (Prolactin-releasing hormone), and decrese PIH (prolactin-inhibiting hormone). PRH acts over the anterior pituitary to stimulate breast milk production through the production of prolactin. While, PIH inhibits prolactin, and thereby, milk production. In this way, it increases the production of the hormone prolactin.