Choose the correct order of the phrases below to explain the response of the body to a decline in serum calcium levels.Choose the BEST answer.
1)increased release of PTH
2)decreased release of PTH
3)increased synthesis of calbindin
4)increased synthesis of 1,25-(OH)₂ D₃
5)increased bone absorption
6)increased calcium absorption
7)decreased bone resorption
8)increased calcium excretion
9)increased bone resorption

Question

Quizplus · Accepted Answer

When serum calcium levels decline, the body responds by increasing the release of parathyroid hormone (PTH) to stimulate calcium absorption from the gut through increased synthesis of 1,25-(OH)₂ D₃, which also increases calcium absorption from the kidneys. In addition, there is an increase in bone resorption to release stored calcium from the bone into the bloodstream. To counteract the effects of the PTH on bone resorption, there is an increase in the synthesis of calbindin to reduce calcium excretion in the urine, which helps maintain serum calcium levels. Therefore, the correct order is 1, 4, 3, 6, 9, and 7.

Choose the Correct Order of the Phrases Below to Explain