Question

The blood calcium level is lowered by the deficiency of
A. Both calcitonin and parathormone
B. Calcitonin
C. Parathormone
D. Thyroxine

Answer 1

Calcitonin and parathyroid regulates blood sugar levels. Level of calcium in blood increases the secretion of calcitonin in higher quantities and vice versa. The release of calcium is stimulated by parathyroid. Thyroxine regulates iodine levels in the body.

Complete answer:
The chief cells of the parathyroid secrete parathormone that regulates the metabolism of calcium and phosphate. Calcium absorption from the intestine and reabsorption from nephrons of the kidney increases by this hormone. In case, there is a deficiency of this hormone, blood calcium levels also decrease.
Calcitonin is a hormone that is produced in humans by the parafollicular cells of the thyroid glands. It helps in regulating levels of calcium and phosphate in the blood. It opposes the action of parathyroid hormone. It reduces the level of calcium in the blood. It inhibits the activity of osteoclasts and decreases the reabsorption of calcium in the kidneys.
Thyroxine hormone is secreted by thyroid gland. It regulates the iodine concentration in the body. It controls the digestion, rate of heart and muscles work, brain development and bone health. Many of the functions slow down when there is a deficiency of thyroxine.
From the above information we have found that blood calcium levels lowers by the deficiency of parathormone.

Hence, the correct answer is option (C).

Note: Level of both calcitonin and parathyroid hormone is determined by the level of calcium in the blood. Parathyroid glands ensure the nervous system and the body’s muscle can work properly and bones remain strong. Hyperparathyroidism can kill people in just 20 or so years. Somatostatin inhibits the secretion of calcitonin. It can also cause medullary thyroid cancer. No clinical effects are observed on the body while having too little calcitonin.