Final answer:
TSH, secreted by the anterior pituitary gland, regulates the thyroid gland's secretion of the hormones T3 and T4, which control basal metabolic rate, functioning under a negative feedback loop initiated by TRH from the hypothalamus.
Step-by-step explanation:
The Thyroid-Stimulating Hormone (TSH), also known as thyrotropin, is a crucial regulatory hormone produced by the anterior pituitary gland. It plays a significant role in controlling the endocrine function of the thyroid gland, which secretes the hormones thyroxine (T4) and triiodothyronine (T3). These thyroid hormones are vital for regulating the body's basal metabolic rate. The production of TSH is stimulated by thyrotropin-releasing hormone (TRH) from the hypothalamus. This system operates on a negative feedback loop in which increased levels of T3 and T4 inhibit the production and release of TSH, hence regulating the secretion of these thyroid hormones.