Final answer:
Parathyroid hormone (PTH) plays a vital role in calcium homeostasis, involving bone resorption by osteoclasts, calcium reabsorption in kidney tubules, and promoting calcium absorption in the small intestine via vitamin D synthesis.
Step-by-step explanation:
Parathyroid Hormone and Its Functions
The hormone in question is parathyroid hormone (PTH), which is essential for calcium homeostasis.
- PTH stimulates osteoclast proliferation and bone resorption, releasing calcium into the bloodstream.
- It also promotes reabsorption of calcium in the kidney tubules, conserving calcium levels in the body.
- Additionally, PTH indirectly increases calcium absorption in the small intestine by stimulating the synthesis of calcitriol, an active form of vitamin D, thus enhancing the intestines' ability to absorb calcium from digested food.
These mechanisms work together to maintain adequate levels of calcium in the blood, which is crucial for various physiological processes, including bone health and muscle function.