Question

Parathormone is involved in calcium balance in the body. Which of the following organs does it act on?

• A. Bones
• B. Kidneys
• C. Gastrointestinal tract
• D. All the above

Answer 1

The correct option is D

All the above

Parathyroid hormone (PTH) increases the Ca++ levels in the blood. PTH acts on bones and stimulates the process of bone resorption (dissolution/demineralisation). PTH also stimulates reabsorption of Ca++ by the renal tubules and increases Ca++ absorption from food in the intestine. It is, thus, clear that PTH is a hypercalcemic hormone, i.e., it increases the blood Ca++ levels.