Which of the Following is a Function of Parathyroid Hormone

Question

Which of the following is a function of parathyroid hormone?
A) It causes the excretion of calcium in the urine.
B) It stimulates osteoblastic activity to form bone.
C) It stimulates the thyroid gland to secrete calcitonin.
D) It increases plasma levels of calcium.

Accepted Answer

Parathyroid hormone increases plasma levels of calcium by increasing its release from bones, decreasing its excretion in the urine, and stimulating the kidneys to convert vitamin D into its active form, which promotes calcium absorption in the intestines. It does not stimulate osteoblastic activity to form bone, and it actually has the opposite effect of calcitonin, which decreases plasma levels of calcium.