MEDICAL PHYSIOLOGY

Detailed explanation-1: -Calcitonin is a hormone that your thyroid gland makes and releases to help regulate calcium levels in your blood by decreasing it. Calcitonin opposes the actions of the parathyroid hormone, which is a hormone that increases your blood calcium levels.

Detailed explanation-2: -Calcitonin is secreted by the parafollicular cells of the thyroid gland. This hormone opposes the action of the parathyroid glands by reducing the calcium level in the blood. If blood calcium becomes too high, calcitonin is secreted until calcium ion levels decrease to normal.

Detailed explanation-3: -When levels of calcium in the blood decrease, this causes the amount of calcitonin secreted to decrease too. The secretion of calcitonin is also inhibited by the hormone somatostatin, which can also be released by the C-cells in the thyroid gland.

Detailed explanation-4: -Calcitonin secretion is stimulated by increases in the serum calcium concentration and calcitonin protects against the development of hypercalcemia.