Which cells remove bone, causing bones resorption?

• A. Osteoblasts
• B. Bone densitometry
• C. Bone mineral content (BMC)
• D. Osteoclasts

Answer: (D)

Bone resorption is carried out by specialized cells that break down bone tissue. These cells attach to the bone surface and release acid and enzymes that dissolve the mineral component and degrade the organic matrix, effectively removing bone in areas where remodeling is needed. This process is the counterpart to bone formation, which is done by cells that build new bone. The activity of the resorbing cells is tightly regulated by signaling factors and hormones that tip the balance toward or away from bone loss. Tools that measure bone density or mineral content assess the amount of mineral or density in bone rather than describing the cellular activity of resorption.