How do compact bone and cancellous bone differ?

Compact bone and cancellous bone are the two primary types of bone tissue, differing significantly in structure, function, and location within the human skeleton.

Structural Differences

• Compact Bone: This is a dense, hard tissue that makes up approximately 80 percent of the skeleton. It is characterized by a lamellar (layered) structure organized into osteons, which contain vascular canals to supply osteocytes with blood.12
• Cancellous Bone: Also known as spongy bone, this tissue is light and porous, comprising about 20 percent of the skeleton. It features a honeycombed, three-dimensional latticework of bony processes called trabeculae, which enclose spaces often filled with marrow and blood vessels.13

Functional Roles

• Compact Bone: Provides strength and rigidity, forming a protective shell around cancellous bone. It is the primary component of long bones where mechanical stress is high.13
• Cancellous Bone: Offers structural support and flexibility while reducing overall weight. Its open structure allows it to dampen sudden stresses, particularly at joints.3