Which is TRUE regarding calcitonin?

Correct Answer: B

Rationale: Calcitonin increases renal Ca2+ excretion and decreases blood Ca2+ by promoting bone deposition, not resorption. It's stimulated by high Ca2+ and gastrin, not decreased gastrin or CCK2.

Correct Answer: C

Rationale: LDL primarily contains apolipoprotein B-100, distinguishing it from chylomicrons (B-48).

Correct Answer: A

Rationale: Cl^- activates salivary α-amylase; its optimum pH is ~6.9, it produces maltose (not glucose), and targets α-1-4 linkages, not lipids.

Correct Answer: C

Rationale: The renal threshold for glucose is ~180 mg/dL, above which glycosuria occurs.

Correct Answer: B

Rationale: Cortisol is the corticoid that counteracts the inflammatory process. Thyroxine is secreted by the thyroid gland. Insulin is secreted by the beta cells of the pancreas. It is responsible for regulation of blood glucose levels. Norepinephrine is secreted by the adrenal medulla in response to stimulation from the sympathetic nervous system. It functions as a pressor (causing blood vessel constriction) hormone to maintain blood pressure.