Dwarfism may be the result of a deficiency of

Correct Answer: D

Rationale: Deficiencies in GHRH, GH, or somatomedins can cause dwarfism.

Correct Answer: D

Rationale: Conn's syndrome (primary hyperaldosteronism) causes K^+ depletion due to excess aldosterone. The medulla isn't essential, the cortex is ~90% of the gland, and 17α-hydroxylase is in zona fasciculata/reticularis.

Correct Answer: D

Rationale: Calcitonin secretion is stimulated by gastrin, CCK, secretin, and glucagon, all of which respond to high Ca2+ or digestive signals.

Correct Answer: B

Rationale: Thiamine deficiency causes beriberi (wet or dry), affecting nerves and heart; other options relate to different vitamin deficiencies.

Correct Answer: D

Rationale: Gastrin promotes mucosal growth; G cells (not TG) secrete gastrin, secretin family includes CCK and VIP, G_{17} is principal, and G_{34} has a longer half-life.