Final answer:
A hypophysectomized animal would experience decreased thyroid hormones due to the lack of thyroid-stimulating hormone (TSH) from the removed pituitary gland, affecting the hormonal balance particularly in the hypothalamic-pituitary-thyroid axis.
Step-by-step explanation:
The correct option : b
In a hypophysectomized (pituitary gland removed) animal, you would expect a significant change in the hormone levels. Specifically, you would see decreased thyroid hormones as a direct effect of the surgery.
The pituitary gland is responsible for the secretion of thyroid-stimulating hormone (TSH), which stimulates the thyroid gland to release thyroid hormones (T3 and T4). Without TSH due to hypophysectomy, the thyroid gland is not stimulated to produce its hormones, leading to decreased levels in the bloodstream. This result is closely connected with the hypothalamic-pituitary-thyroid axis. In addition, the removal of the pituitary gland also results in lower levels of growth hormone (GH), adrenocorticotropic hormone (ACTH), and other hormones regulated by the anterior pituitary, including those produced by the hypothalamus and regulating other endocrine glands.