<P> The thyroid gland also produces the hormone calcitonin , which helps regulate blood calcium levels . Parafollicular cells produce calcitonin in response to high blood calcium . Calcitonin decreases the release of calcium from bone , by decreasing the activity of osteoclasts , cells which break down bone . Bone is constantly reabsorbed by osteoclasts and created by osteoblasts , so calcitonin effectively stimulates movement of calcium into bone . The effects of calcitonin are opposite those of the parathyroid hormone ( PTH ) produced in the parathyroid glands . However , calcitonin seems far less essential than PTH , as calcium metabolism remains clinically normal after removal of the thyroid ( thyroidectomy ) , but not the parathyroid glands . </P>
<P> The thyroid gland also produces the hormone calcitonin , which helps regulate blood calcium levels . Parafollicular cells produce calcitonin in response to high blood calcium . Calcitonin decreases the release of calcium from bone , by decreasing the activity of osteoclasts , cells which break down bone . Bone is constantly reabsorbed by osteoclasts and created by osteoblasts , so calcitonin effectively stimulates movement of calcium into bone . The effects of calcitonin are opposite those of the parathyroid hormone ( PTH ) produced in the parathyroid glands . However , calcitonin seems far less essential than PTH , as calcium metabolism remains clinically normal after removal of the thyroid ( thyroidectomy ) , but not the parathyroid glands . </P>
ct is produced by which cells of the thyroid gland
ct is produced by which cells of the thyroid gland
Parafollicular cells
Parafollicular cells