Which of the following is NOT true about osteoclasts?

Osteoclasts are specialized cells responsible for the resorption or breakdown of bone tissue. This process is crucial for bone remodeling, which is the continuous cycle of bone formation and resorption that maintains bone health and structure throughout an individual's life. By breaking down bone tissue, osteoclasts help regulate the release of minerals, including calcium, into the bloodstream, thus playing a significant role in maintaining calcium homeostasis in the body.

While osteoclasts do contribute to regulating calcium levels in conjunction with other cells like osteoblasts, they do not secrete calcitonin. Calcitonin is actually a hormone produced by the thyroid gland, which helps lower blood calcium levels by inhibiting the activity of osteoclasts, thereby reducing bone resorption. This distinction clarifies why the statement regarding the secretion of calcitonin by osteoclasts is not true. Understanding the specific functions of osteoclasts and their role in the hormonal regulation of calcium levels is essential for grasping bone physiology and its implications in conditions like osteoporosis and hypercalcemia.