TSN secretion is stimulated by:

Correct Answer: C

Rationale: Assuming 'TSN' is a typo for TSH (thyroid-stimulating hormone), cold temperatures stimulate its release via TRH. Dopamine and somatostatin inhibit it, stress has variable effects, and glucocorticoids suppress it.

Correct Answer: C

Rationale: Ketone bodies form during glucose deficiency (e.g., fasting), are acids, but are metabolized by extrahepatic tissues, not easily in the liver.

Correct Answer: B

Rationale: VIP (vasoactive intestinal peptide) relaxes smooth muscle and increases intestinal water/electrolyte secretion.

Correct Answer: D

Rationale: Parathormone, or parathyroid hormone, is produced and secreted by the parathyroid glands. Low calcium levels will stimulate release of parathyroid hormone, which increases the plasma level of calcium. Parathormone acts on the renal tubules to increase the excretion of phosphorus in the urine and to stimulate the reabsorption of calcium. Parathormone also acts on bone, causing the release of calcium from the bone into the bloodstream.

Correct Answer: A

Rationale: Hyperplasia (increased cellular growth) is the usual cause of hypersecretion of an endocrine gland.