What happens to bone when mechanical loading is applied?

What happens to bone when mechanical loading is applied?

• A. Cartilage forms at the loaded site
• B. Blood vessels proliferate causing bone expansion without modeling
• C. Osteoblasts migrate to the bone surface and begin bone modeling
• D. Osteoclasts resorb bone at the loaded site

Answer: (C)

Mechanical loading prompts bone to adapt by forming new bone at the loaded surfaces to strengthen the structure. Osteocytes sense the strain and signaling cascades recruit osteoblasts to the bone surface, where they lay down new bone matrix—this is bone modeling in response to load. This active formation at the loaded site makes the bone more resilient to future stresses. Cartilage formation isn’t the direct outcome of normal loading on mature bone; cartilage is central during development or fracture healing. Proliferation of blood vessels causing bone to expand without modeling doesn’t capture the targeted formation of new bone at the loaded surface. Resorption by osteoclasts at the loaded site would weaken the bone rather than strengthen it and is more associated with disuse or specific pathological states, not typical mechanical loading adaptation.

Mechanical loading prompts bone to adapt by forming new bone at the loaded surfaces to strengthen the structure. Osteocytes sense the strain and signaling cascades recruit osteoblasts to the bone surface, where they lay down new bone matrix—this is bone modeling in response to load. This active formation at the loaded site makes the bone more resilient to future stresses.

Cartilage formation isn’t the direct outcome of normal loading on mature bone; cartilage is central during development or fracture healing. Proliferation of blood vessels causing bone to expand without modeling doesn’t capture the targeted formation of new bone at the loaded surface. Resorption by osteoclasts at the loaded site would weaken the bone rather than strengthen it and is more associated with disuse or specific pathological states, not typical mechanical loading adaptation.