Calcitonin functions to lower calcium and phosphate ion concentration by inhibiting which type of cells?

Calcitonin is a hormone produced by the thyroid gland that plays a crucial role in calcium homeostasis. Its primary function is to reduce the concentration of calcium and phosphate ions in the blood. It achieves this by inhibiting the activity of osteoclasts, which are specialized cells responsible for bone resorption. Osteoclasts break down bone tissue, releasing calcium and phosphate ions into the bloodstream. By inhibiting these cells, calcitonin decreases the mobilization of calcium and phosphate from the bones, therefore contributing to lower levels of these ions in circulation.

In conjunction with the actions of parathyroid hormone (PTH), which increases calcium levels by stimulating osteoclasts, calcitonin acts as a counterbalance to help maintain calcium balance in the body. This regulation is vital for various physiological processes, including bone health and metabolic functions.