As we grow, our long bones increase in diameter, but the thickness of the compact bone of the shaft remains relatively constant. Explain this phenomenon.

Key Concepts

Bone Growth and Remodeling

Bone growth occurs through a process called remodeling, where old bone tissue is replaced with new tissue. This process is regulated by various factors, including mechanical stress and hormonal signals. As long bones grow in length and diameter, the inner bone structure adapts to maintain strength while allowing for increased size.

Compact Bone Structure

Compact bone, also known as cortical bone, is dense and forms the outer layer of bones. It provides strength and support, allowing bones to withstand stress. The thickness of compact bone remains relatively constant during growth because it is balanced by the processes of bone formation and resorption, ensuring structural integrity.

Wolff's Law

Wolff's Law states that bone adapts to the loads under which it is placed. When mechanical stress is applied to a bone, it remodels itself to become stronger in response. This principle explains why the diameter of long bones increases while maintaining a consistent thickness of compact bone, as the bone adapts to support increased weight and activity.