Question

The blood calcium level falls too low because

• A. The thyroid gland releases calcitonin, which binds to bone cells
• B. The parathyroid glands release PTH, which binds to kidney cells
• C. The thyroid gland releases thyroid hormone, which binds to small intestine cells
• D. The pancreas releases glucagon, which binds to liver cells
• E. The pituitary gland releases growth hormone, which binds to bone cells

Answer 1

The correct option is A The thyroid gland releases calcitonin, which binds to bone cells

Parathormone of parathyroid gland increases the blood calcium level by binding to receptors present on DCT of the nephron to stimulate conditional reabsorption of calcium. Thyroid hormone does not have any specific target cell and stimulate metabolic rate by all cells. Glucagon regulates blood glucose level while growth hormone stimulate overall growth and development. Calcitonin hormone stimulates a temporary reduction in number and activity of osteoclasts (bone cells) and thereby reducing the blood calcium level. Thus, the correct answer is option A.