Bone remodeling in adults is regulated and directed mainly by a. growth hormone b. thyroid hormones c. sex hormones d. mechanical stress e. PTH.

Video transcript

Welcome back. Here's our next question. The hormone that regulates calcium and phosphate levels in the body through bone resorption is called a Calcitonin B, parathormone C estrogen or D thyroxine. The hormone we're looking for here is choice B, parathormone. It's also known as parathyroid hormone or P T H. And it does indeed stimulate bone resorption, which then causes the release of calcium and phosphate into the bloodstream. It also regulates calcium levels by increasing calcium absorption in the intestines and decreasing the amount of calcium excreted by the kidneys. The other hormone that's involved in regulating calcium levels is, and as we might see in the name calcitonin, but Calcitonin works in a different way. It decreases the amount of calcium in the bloodstream by promoting calcium deposition in the bones through the formation of new bones. It also reduces calcium resorption in the kidneys. But we're looking for the hormone that regulates those levels through bone resorption. So that's why calcitonin isn't the correct answer. Estrogen has a role in muscle health by promoting muscle muscle synthesis and helping to stimulate muscle repair. But that's not what we're looking for. We're looking for that regulation of calcium levels. So cross off choice c then finally choice d thyroxine, excuse me, thyroxine. It's produced by thyroid and it helps to regulate the metabolic rate. And that of course, affects mus muscle function, but it doesn't regulate calcium levels. So we cross that out. So the hormone that regulates calcium and phosphate levels through bone resorption is choice b parathormone. See you in the next video.