20. Name the endocrine gland that produces calcitonin and mention the role played by this hormone.
Calcitonin/thyrocalcitonin is a 32 amino acid, linear polypeptide hormone that is produced in humans primarily by the parafollicularcells of the thyroid gland. It checks excess Ca2+ and phosphate in plasma by decreasing mobilisation from bones.
Deficiency of calcitonin results in osteoporesis or loss of bone density (due to dissolution of parathormone)