If an autoimmune disorder targets the alpha cells, production of which hormone would be directly affected?

Correct Answer: D

Rationale: Alpha cells in the pancreas produce glucagon to raise blood glucose. Autoimmune targeting would impair glucagon, not somatostatin (delta cells), pancreatic polypeptide (PP cells), or insulin (beta cells). Glucagon's direct link to alpha cells distinguishes it, critical for glucose counterregulation, contrasting with other pancreatic hormones.

Correct Answer: C

Rationale: Follicle-stimulating hormone (FSH) from the anterior pituitary stimulates spermatogenesis in male testes' Sertoli cells and follicle growth in female ovaries monthly, driving gamete production. Luteinizing hormone (LH) triggers testosterone in males and ovulation/oestradiol in females, not sperm/follicle initiation. Somatostatin inhibits hormone release (e.g., GH), not stimulating reproduction. Thymosin, from the thymus, boosts immunity, not gonadal function. FSH's dual reproductive role distinguishes it, key to fertility, unlike ovulation, inhibition, or immune hormones.

Correct Answer: D

Rationale: Goiter, thyroid enlargement, stems from multiple causes: iodine deficiency impairs T3/T4 synthesis, increasing TSH and colloid; genetic abnormalities (e.g., enzyme defects) disrupt hormone production; anti-thyroid drugs (e.g., propylthiouracil) block synthesis, prompting hypertrophy. 'All' encompasses these, distinguishing goiter's multifactorial etiology, key to diagnosis, contrasting with single-cause disorders.

Correct Answer: D

Rationale: The thyroid gland sits at the throat's base, below the Adam's apple, secreting T3/T4 for metabolism and calcitonin for calcium. The pituitary, at the brain's base, controls other glands. The pineal, in the brain's midline, releases melatonin. The hypothalamus, above the pituitary, regulates it, not at the throat. Thyroid's neck location and metabolic role distinguish it, key to its anatomical and functional identity, unlike brain-based glands.

Correct Answer: C

Rationale: The pancreas is both endocrine (islets secrete insulin/glucagon into blood) and exocrine (acini release digestive enzymes via ducts). Thyroid (T3/T4) and thymus (thymosin) are purely endocrine, lacking ducts. Pituitary (e.g., GH) is endocrine-only, no exocrine function. Pancreas' dual role distinguishes it, essential for metabolic and digestive integration, unlike single-function glands.