Question

Blood calcium levels are maintained because the bones act as a calcium sink in which calcium can either be stored or procured based on the body's needs. If a person secretes too much parathyroid hormone (one possible factor in the bone disease osteoporosis), what happens to calcium levels in the body?
A. Bone stores are depleted, and the kidney moves calcium.
B. Bone stores are depleted and the kidney retains calcium.
C. Blood levels of calcium may read high
D. Both [b] and [c]

Answer 1

Hint: Parathyroid hormone is a polypeptide that is synthesized and cleaved into an active form inside the parathyroid gland. Parathyroid hormone is directly implicated in kidneys, bones, and small intestines. In the bones, PTH stimulates the discharge of calcium in an indirect process by osteoclasts which eventually results in the resorption of the bones.
Complete Step-by-step answer: Calcium is one of the most important minerals of the body. The kidney plays a key role in calcium homeostasis by reabsorbing filtered calcium in quantities that undergo control through calciotropic hormones, and PTH. Some calcium is lost from the body every day by the kidneys and expelled through urine.
The parathyroid hormone secreted from the parathyroid gland is liable to control blood calcium levels. It is secreted in response to low calcium levels in the blood and promotes the release of calcium ions from the bones and calcium absorption from the intestine thereby maintaining the blood calcium level. Thyrocalcitonin (TCT) is secreted once the calcium level in the blood is high. It then reduces the levels by suppressing the release of calcium ions from bones.
Excess of parathyroid hormone raises blood calcium levels by raising and mobilizing calcium from bones to blood. Thus, it results in the depletion of the calcium stores of the body.
Hypercalcemia is a condition caused by above-average calcium levels in the blood. Too much calcium in the blood will weaken our bones, cause muscle weakness, kidney stones, and disrupt the functions of the brain and heart.
Therefore the correct answer is Option D.
Note: Calcium helps build strong teeth and bones. It is essential for heart function and helps in blood clotting, muscle contraction, and nerve signaling. The normal range for the total blood calcium in the body is between 8.6 and 10.2 milligrams per decilitre (mg/dL).