Which thyroid cells secrete calcitonin?

Which thyroid cells secrete calcitonin?

• A. Parafollicular (C) Cells
• B. Follicular Cells
• C. Parathyroid Chief Cells
• D. Oxyphil Cells

Answer: (A)

Calcitonin is produced by the parafollicular cells, also known as C cells, of the thyroid. These cells sit in the interfollicular stroma, distinct from the follicular cells that make thyroid hormones T3 and T4. When calcium levels rise, C cells release calcitonin, which helps lower blood calcium by inhibiting osteoclast activity in bone and reducing calcium reabsorption in the kidneys. The follicular cells are involved in thyroid hormone synthesis, not calcitonin. Parathyroid chief cells secrete parathyroid hormone, which raises calcium, and oxyphil cells are an auxiliary cell type with no primary role in secreting calcitonin.

Calcitonin is produced by the parafollicular cells, also known as C cells, of the thyroid. These cells sit in the interfollicular stroma, distinct from the follicular cells that make thyroid hormones T3 and T4. When calcium levels rise, C cells release calcitonin, which helps lower blood calcium by inhibiting osteoclast activity in bone and reducing calcium reabsorption in the kidneys. The follicular cells are involved in thyroid hormone synthesis, not calcitonin. Parathyroid chief cells secrete parathyroid hormone, which raises calcium, and oxyphil cells are an auxiliary cell type with no primary role in secreting calcitonin.