The production of FSH by the anterior pituitary is reduced by which hormone?

Correct Answer: D

Rationale: Inhibin, from gonadal Sertoli/granulosa cells, selectively inhibits follicle-stimulating hormone (FSH) release via negative feedback, regulating gametogenesis. Estrogens and progesterone broadly suppress pituitary hormones (including FSH), relaxin aids childbirth. Inhibin's specific FSH targeting distinguishes it, key to reproductive homeostasis, contrasting with broader gonadal feedback.

Correct Answer: D

Rationale: T3 (triiodothyronine) and T4 (thyroxine) from the thyroid increase metabolic rate, stimulating cellular energy use body-wide, boosting oxygen consumption and heat production. Glucose reduction is insulin's role, not thyroid hormones'. Calcitonin, also thyroid-derived from C-cells, lowers blood calcium, unrelated to T3/T4's metabolic focus. Bone growth depends on growth hormone (GH) from the pituitary, not thyroid though T3/T4 support growth indirectly via metabolism. Their metabolic acceleration distinguishes them, essential for energy regulation, unlike glucose, calcium, or growth-specific functions.

Correct Answer: A

Rationale: Gigantism occurs when excess growth hormone (GH) from the pituitary stimulates epiphyseal cartilage growth before puberty, causing excessive height. Renal tubule issues define diabetes insipidus, low target gland stimulation relates to hypopituitarism (e.g., Simmond's), and prolactin excess causes hyperprolactinemia. Gigantism's link to GH and open growth plates distinguishes it, key to pediatric endocrinology, contrasting with post-closure acromegaly or unrelated hormone disorders.

Correct Answer: D

Rationale: Adenomas, benign tumors, cause acromegaly via pituitary GH oversecretion, not hyperthyroidism (often Graves' or thyroid adenoma), hypothyroidism (deficiency), or adrenal tumors (pheochromocytoma). The answer 'hyperthyroidism' seems erroneous; acromegaly fits adenoma etiology. This pituitary link distinguishes it, key to tumor-related endocrinopathies, contrasting with thyroid or adrenal origins.

Correct Answer: C

Rationale: Salivary glands are exocrine, secreting saliva via ducts for digestion, not hormones into blood. Pancreas (insulin), testes (testosterone), and parathyroid (PTH) are endocrine, releasing hormones systemically for glucose, reproduction, and calcium regulation. Salivary's ducted, non-hormonal output distinguishes it, contrasting with endocrine glands' blood-mediated roles, key to gland classification.