Chapter 17 - Section 17.2 - Study Guide - Assess Your Learning Outcomes - Page 669: 3

The hypothalamus secretes several hormones that regulate the anterior pituitary gland's activity. These hormones are known as releasing hormones or inhibiting hormones, and they play a crucial role in controlling the secretion of various hormones from the anterior pituitary. Here are six important hormones secreted by the hypothalamus, along with their effects on the anterior pituitary and the subsequent target glands: 1. **Corticotropin-Releasing Hormone (CRH):** - Effect: Stimulates the anterior pituitary to release adrenocorticotropic hormone (ACTH). - Target Gland: Adrenal cortex. - Function: ACTH stimulates the adrenal cortex to release glucocorticoid hormones, such as cortisol, which are involved in stress response, metabolism, and immune regulation. 2. **Thyrotropin-Releasing Hormone (TRH):** - Effect: Stimulates the anterior pituitary to release thyroid-stimulating hormone (TSH). - Target Gland: Thyroid gland. - Function: TSH stimulates the thyroid gland to produce and release thyroid hormones (T3 and T4), which regulate metabolism, growth, and energy balance. 3. **Gonadotropin-Releasing Hormone (GnRH):** - Effect: Stimulates the anterior pituitary to release gonadotropins—luteinizing hormone (LH) and follicle-stimulating hormone (FSH). - Target Glands: Gonads (ovaries in females, testes in males). - Function: LH and FSH regulate the reproductive system. In females, they control ovarian function and the menstrual cycle. In males, they stimulate testicular function and sperm production. 4. **Prolactin-Releasing Hormone (PRH) and Prolactin-Inhibiting Hormone (PIH, Dopamine):** - Effect: PRH stimulates the release of prolactin, while PIH inhibits its release. - Target Gland: Anterior pituitary. - Function: Prolactin is involved in milk production and breast development during pregnancy and after childbirth. 5. **Growth Hormone-Releasing Hormone (GHRH) and Somatostatin (Growth Hormone-Inhibiting Hormone):** - Effect: GHRH stimulates the release of growth hormone (GH), while somatostatin inhibits its release. - Target Gland: Liver, bones, and other tissues. - Function: GH promotes growth, cell reproduction, and regeneration. It also affects metabolism and plays a role in maintaining muscle and bone health. These hypothalamic hormones are released in response to various signals from the body, such as changes in hormone levels, physiological conditions, and external stimuli. Their precise regulation helps maintain a balance in hormone levels and ensures proper functioning of the endocrine system, as they influence the release of hormones from the anterior pituitary, which in turn regulate various physiological processes throughout the body.

The hypothalamus secretes several hormones that regulate the anterior pituitary gland's activity. These hormones are known as releasing hormones or inhibiting hormones, and they play a crucial role in controlling the secretion of various hormones from the anterior pituitary. Here are six important hormones secreted by the hypothalamus, along with their effects on the anterior pituitary and the subsequent target glands: 1. **Corticotropin-Releasing Hormone (CRH):** - Effect: Stimulates the anterior pituitary to release adrenocorticotropic hormone (ACTH). - Target Gland: Adrenal cortex. - Function: ACTH stimulates the adrenal cortex to release glucocorticoid hormones, such as cortisol, which are involved in stress response, metabolism, and immune regulation. 2. **Thyrotropin-Releasing Hormone (TRH):** - Effect: Stimulates the anterior pituitary to release thyroid-stimulating hormone (TSH). - Target Gland: Thyroid gland. - Function: TSH stimulates the thyroid gland to produce and release thyroid hormones (T3 and T4), which regulate metabolism, growth, and energy balance. 3. **Gonadotropin-Releasing Hormone (GnRH):** - Effect: Stimulates the anterior pituitary to release gonadotropins—luteinizing hormone (LH) and follicle-stimulating hormone (FSH). - Target Glands: Gonads (ovaries in females, testes in males). - Function: LH and FSH regulate the reproductive system. In females, they control ovarian function and the menstrual cycle. In males, they stimulate testicular function and sperm production. 4. **Prolactin-Releasing Hormone (PRH) and Prolactin-Inhibiting Hormone (PIH, Dopamine):** - Effect: PRH stimulates the release of prolactin, while PIH inhibits its release. - Target Gland: Anterior pituitary. - Function: Prolactin is involved in milk production and breast development during pregnancy and after childbirth. 5. **Growth Hormone-Releasing Hormone (GHRH) and Somatostatin (Growth Hormone-Inhibiting Hormone):** - Effect: GHRH stimulates the release of growth hormone (GH), while somatostatin inhibits its release. - Target Gland: Liver, bones, and other tissues. - Function: GH promotes growth, cell reproduction, and regeneration. It also affects metabolism and plays a role in maintaining muscle and bone health. These hypothalamic hormones are released in response to various signals from the body, such as changes in hormone levels, physiological conditions, and external stimuli. Their precise regulation helps maintain a balance in hormone levels and ensures proper functioning of the endocrine system, as they influence the release of hormones from the anterior pituitary, which in turn regulate various physiological processes throughout the body.