Question

Parathyroid hormone (PTH) increases the $C{a}^{2+}$ levels in the blood by
a. Bone resorption/dissolution/demineralisation
b. Reabsorption of $C{a}^{2+}$ by the renal tubules
c. Increasing $C{a}^{2+}$ absorption from the digested food

• A. a and b
• B. b and c
• C. a and c
• D. a, b and c

Answer 1

Answer: (D)

• Parathyroid hormone (PTH) increases the $C{a}^{2+}$ levels in the blood. PTH acts on bones and stimulates the process of bone reabsorption (dissolution/demineralisation).
• PTH also stimulates reabsorption of $C{a}^{2+}$ by the re nal tubules and increases $C{a}^{2+}$ absorption from the digested food.
• It is, thus, clear that PTH is a hypercalcemic hormone, i.e., it increases the blood $C{a}^{2+}$ levels.