Describe the bone remodeling cycle and coordination of osteoclasts and osteoblasts after microdamage.

Describe the bone remodeling cycle and coordination of osteoclasts and osteoblasts after microdamage.

• A. Osteoclasts resorb damaged bone; osteoblasts fill resorption cavities with new bone; remodeling replaces woven bone with lamellar bone, maintaining strength.
• B. Osteoblasts resorb damaged bone; osteoclasts fill resorption cavities; remodeling replaces woven bone with lamellar bone.
• C. Remodeling occurs without any resorption.
• D. Osteoclasts and osteoblasts work independently with no coordination.

Answer: (C)

The main idea is that bone repair after microdamage happens through a coordinated remodeling sequence: osteoclasts first resorb the damaged bone, and then osteoblasts come in to form new bone in that spot. This resorption-and-formation cycle, carried out by a basic multicellular unit, restores the structure and strength of the bone. When microdamage is detected, signals recruit osteoclasts to the damaged area to carve out a resorption cavity. After the area is cleared, osteoblasts lay down new bone matrix (osteoid) and mineralize it to fill the pit. The new bone starts as woven bone, which is laid down quickly but is disorganized and not as strong. Over time, this is remodeled into lamellar bone, whose orderly collagen organization and layered structure give greater strength and resilience. This coordinated sequence is why remodeling involves both resorption and formation rather than just one process in isolation, and why the final lamellar bone helps maintain the bone’s mechanical integrity in the affected region.

The main idea is that bone repair after microdamage happens through a coordinated remodeling sequence: osteoclasts first resorb the damaged bone, and then osteoblasts come in to form new bone in that spot. This resorption-and-formation cycle, carried out by a basic multicellular unit, restores the structure and strength of the bone.

When microdamage is detected, signals recruit osteoclasts to the damaged area to carve out a resorption cavity. After the area is cleared, osteoblasts lay down new bone matrix (osteoid) and mineralize it to fill the pit. The new bone starts as woven bone, which is laid down quickly but is disorganized and not as strong. Over time, this is remodeled into lamellar bone, whose orderly collagen organization and layered structure give greater strength and resilience.

This coordinated sequence is why remodeling involves both resorption and formation rather than just one process in isolation, and why the final lamellar bone helps maintain the bone’s mechanical integrity in the affected region.