Hypothalamus and Pituitary Gland Functions

Hypothalamus and Pituitary Function

• The main function of the hypothalamus is to respond to external and internal signals, integrating various physiological and psychological processes to maintain homeostasis.

Hypothalamo-Hypophyseal Portal System

• The hypothalamo-hypophyseal portal blood vessels connect the hypothalamus and the anterior pituitary, allowing for the exchange of hormones and regulatory factors.

Pituitary-Adrenal Axis

• The main stimulatory factor involved in the control of the pituitary-adrenal axis is adrenocorticotropic hormone (ACTH).

Feedback Regulation of Hormone Secretion

• Hormones produced by target glands controlled by the anterior pituitary affect the secretion of corresponding hypothalamic or pituitary hormones through negative feedback loops.

Gonadotrophin Regulation

• Gonadotropin-releasing hormone (GnRH) stimulates the release of gonadotrophins LH and FSH from the gonadotroph.

Growth Hormone Regulation

• Somatostatin inhibits the release of growth hormone (GH) by the pituitary.
• Growth hormone-releasing hormone (GHRH) and ghrelin stimulate the release of GH, acting in concert to control both the timing and magnitude of GH release.

Thyrotrophin Regulation

• Thyrotropin-releasing hormone (TRH) controls the secretion of thyrotrophin (TSH) by the thyrotroph cells of the anterior pituitary.

Multiple Hormone Functions

• Prolactin is a multipurpose hormone exerting more than 300 biologic activities, including reproductive, sexual, metabolic, and immune functions.

This quiz covers the functions of the hypothalamus, anterior pituitary, and adrenal glands, exploring their roles in coordinating behavioral and circadian rhythms, as well as enforcing homeostatic mechanisms on target glands. It also discusses the link between the hypothalamus and the endocrine system through the pituitary gland.