Which structure lines the inner surface of bone?

Which structure lines the inner surface of bone?

• A. Endosteum
• B. Periosteum
• C. Endomysium
• D. Perimysium

Answer: (A)

The inner surface of bone is lined by a thin cellular membrane called the endosteum, which lines the medullary cavity and the internal surfaces of bone trabeculae. It contains osteoprogenitor cells that can become osteoblasts, supporting bone growth, remodeling, and repair from within the bone. In contrast, the periosteum covers the outer surface of bone and provides an outer fibrous layer with an inner osteogenic layer for growth in thickness and vascular supply. The endomysium and perimysium are connective tissue layers in skeletal muscle, not bone lining. So the endosteum is the structure that lines the inner surface of bone.

The inner surface of bone is lined by a thin cellular membrane called the endosteum, which lines the medullary cavity and the internal surfaces of bone trabeculae. It contains osteoprogenitor cells that can become osteoblasts, supporting bone growth, remodeling, and repair from within the bone. In contrast, the periosteum covers the outer surface of bone and provides an outer fibrous layer with an inner osteogenic layer for growth in thickness and vascular supply. The endomysium and perimysium are connective tissue layers in skeletal muscle, not bone lining. So the endosteum is the structure that lines the inner surface of bone.