Final answer:
The hormone central to the synthesis and release of thyroid hormones, specifically T3 and T4, is thyroid-stimulating hormone (TSH), which is secreted by the anterior pituitary gland. TSH's production is regulated by TRH from the hypothalamus, and TSH stimulates the thyroid gland, following a negative feedback mechanism to maintain hormone balance.
Step-by-step explanation:
The hormone that plays a crucial role in both the synthesis and release of thyroid hormones (T3 and T4) is thyroid-stimulating hormone (TSH). TSH is secreted by the anterior pituitary gland and is responsible for stimulating the thyroid to produce T3 (triiodothyronine) and T4 (thyroxine).
The synthesis of these thyroid hormones involves the active transport of iodide ions into the thyroid gland, where they are converted to iodine and bound to a glycoprotein called thyroglobulin. This conversion is catalyzed by the enzyme thyroperoxidase in the presence of hydrogen peroxide. The release of T3 and T4 into the bloodstream then follows, which subsequently influences the body's basal metabolic rate.
The production and secretion of TSH itself are regulated by thyrotropin-releasing hormone (TRH) from the hypothalamus, following a negative feedback loop to maintain hormone levels within the physiological range. An increase in T3 and T4 levels inhibits the release of TSH, thereby modulating the synthesis and release of thyroid hormones.