Final answer:
The release of thyroxine involves the hypothalamus secreting TRH, which stimulates the anterior pituitary gland to release TSH. TSH prompts the thyroid gland to produce T3 and T4, which, when at sufficient levels, feedback to inhibit TRH and TSH production. the correct answer is C .
Step-by-step explanation:
The release of thyroxine, also known as T4, begins with the hypothalamus. When the hypothalamus senses a low concentration of thyroid hormones in the blood, it secretes thyrotropin-releasing hormone (TRH). This hormone travels to the anterior pituitary gland, stimulating it to release thyroid-stimulating hormone (TSH). TSH is then transported through the bloodstream to the thyroid gland, which, on receiving TSH, starts the synthesis and release of T3 and T4 hormones.
The process of T4 synthesis involves the binding of TSH to receptors on thyroid follicular cells, triggering the conversion of a glycoprotein called thyroglobulin into T3 and T4 with the aid of iodine. T4 is released in greater amounts than T3, and tissues in the body can convert T4 to the more active T3. This regulation ensures a balance of thyroid hormone levels, maintaining metabolic homeostasis in the body.