Calcitonin, a peptide hormone produced by the thyroid gland's parafollicular (C) cells, regulates blood calcium. Its mechanism involves inhibiting osteoclast activity, which reduces bone resorption and lowers circulating calcium levels. The hormone is essential for preventing hypercalcemia.
| List I | List II |
|---|---|
| (A) Shoulder | (I) Tarsals |
| (B) Thigh | (II) Carpals |
| (C) Wrist | (III) Humerus |
| (D) Ankle | (IV) Femur |