Final answer:
Osteoclasts are important cells in bone that function in the resorption and breakdown of bone tissue. They balance the formation of new bone by osteoblasts through a continual process of bone remodeling. This activity is essential for maintaining healthy bones and regulating calcium levels in the body.
Step-by-step explanation:
Osteoclasts are large cells that are present in the cavities of bone that function in the resorption of bone. These are specialized cells responsible for breaking down old bone tissue, a process necessary for the maintenance and repair of bones. They are characterized by being multinucleated and originate from monocytes and macrophages, which are types of white blood cells, not from osteogenic cells like osteoblasts or osteocytes. Osteoclasts dissolve the minerals in bone, such as calcium and phosphorus, and release them into the blood. This process is essential for regulating calcium levels in the body and for bone remodeling, whereby the skeleton is shaped and tiny flaws in bones are repaired.
The activity of osteoclasts is balanced by that of osteoblasts, which are cells that continuously form new bone. This balance ensures the constant but subtle reshaping of bone through a process known as bone remodeling. The action of osteoclasts is regulated by various hormones, including parathyroid hormone (PTH), thyroid hormones, vitamin D, and is inhibited by hormones like calcitonin and estrogens.