What is the primary purpose of bone remodeling?

• A. To maintain the shape of bones
• B. To remove old bone and replace it with new bone
• C. To increase the strength of bones
• D. To adjust bone density with age

Answer: (B)

The primary purpose of bone remodeling is to remove old bone and replace it with new bone. This dynamic process is essential for maintaining healthy bone tissue throughout a person’s life. Bone remodeling involves the coordinated action of cells called osteoclasts, which resorb old bone, and osteoblasts, which form new bone.

This process allows the skeleton to adapt to changes in mechanical loading, repair microdamage that occurs from everyday activities, and regulate calcium and phosphate levels in the body. Through remodeling, bones can also respond to various physiological factors, such as hormonal changes and nutritional status.

While maintaining the shape of bones, increasing the strength of bones, and adjusting bone density with age are important aspects of bone health, these functions are all secondary effects of the primary purpose of bone remodeling: the continuous cycle of removing old bone and forming new bone to replace it. Thus, the correct answer reflects the fundamental biological mechanism that sustains skeletal integrity and health over time.