Compact bone is primarily found in which location and contributes to what function?

• A. Found in the ends of bones
• B. Found in the shaft of the bone and provides support
• C. Lines the joint capsules
• D. Is the spongy inner tissue

Answer: (B)

Compact bone is the dense, load-bearing tissue that forms the outer shell of most bones. Its tightly packed matrix and organized structure give it the strength to resist bending and twisting, making it ideal for supporting body weight and transferring forces along the bone. In long bones, this dense tissue is most prominent in the shaft (the diaphysis), where it creates the cortical layer that provides structural support. The ends of long bones are primarily spongy (cancellous) bone, with a thinner outer layer of compact bone, which is why statements describing the ends or describing spongy tissue don’t fit as well. Lining joint capsules refers to synovial surfaces, not compact bone. So, the location and function described—shaft location and structural support—best match compact bone.