Which hormone is released by the hypothalamus to stimulate the release of thyroid-stimulating hormone (TSH) from the anterior pituitary?

Thyrotropin-releasing hormone (TRH) is the key hormone released by the hypothalamus that plays a critical role in the regulation of thyroid function. When TRH is secreted, it prompts the anterior pituitary gland to release thyroid-stimulating hormone (TSH). TSH then stimulates the thyroid gland to produce and release thyroid hormones, which are vital for metabolism, growth, and development.

This relationship between TRH and TSH is part of the hypothalamic-pituitary-thyroid axis, a crucial pathway in endocrine regulation. The feedback mechanism ensures that when levels of thyroid hormones are sufficient, TRH secretion is downregulated to maintain balance.

The other hormones listed are closely associated with the regulation of different endocrine functions. Gonadotropin-releasing hormone (GnRH) regulates reproductive hormones; growth hormone-releasing hormone (GHRH) stimulates the secretion of growth hormone; and corticotropin-releasing hormone (CRH) is involved in stress response by stimulating adrenocorticotropic hormone (ACTH) release. Each of these hormones has distinct roles and acts on different target hormones and glands, thereby underscoring the specificity of TRH for stimulating TSH release.