Which tissue lines the marrow cavity and plays a role in bone growth and repair?

Which tissue lines the marrow cavity and plays a role in bone growth and repair?

• A. Endosteum
• B. Periosteum
• C. Articular cartilage
• D. Cancellous tissue

Answer: (A)

The tissue that lines the marrow cavity and plays a significant role in bone growth and repair is the endosteum. The endosteum is a thin vascular membrane that lines the inner surface of the bony tissue, specifically encompassing the marrow cavity. This tissue contains osteoblasts, which are essential for the formation of new bone as well as osteoclasts, which help in the resorption of bone. The endosteum is crucial during processes such as bone remodeling and repairing fractures, as it allows for the action of these bone-forming and bone-resorbing cells. In contrast, the periosteum is a dense layer of vascular connective tissue that surrounds the outer surface of bones, aiding in the attachment of tendons and ligaments, but it does not directly line the marrow cavity. Articular cartilage is found on the surfaces of bones where they come together to form joints, providing a smooth surface for movement and shock absorption, rather than being involved in lining the marrow cavity or contributing directly to growth and repair. Cancellous tissue, or trabecular bone, is the spongy bone found inside bones that contains the marrow but is not a lining tissue like the endosteum.

The tissue that lines the marrow cavity and plays a significant role in bone growth and repair is the endosteum. The endosteum is a thin vascular membrane that lines the inner surface of the bony tissue, specifically encompassing the marrow cavity. This tissue contains osteoblasts, which are essential for the formation of new bone as well as osteoclasts, which help in the resorption of bone. The endosteum is crucial during processes such as bone remodeling and repairing fractures, as it allows for the action of these bone-forming and bone-resorbing cells.

In contrast, the periosteum is a dense layer of vascular connective tissue that surrounds the outer surface of bones, aiding in the attachment of tendons and ligaments, but it does not directly line the marrow cavity. Articular cartilage is found on the surfaces of bones where they come together to form joints, providing a smooth surface for movement and shock absorption, rather than being involved in lining the marrow cavity or contributing directly to growth and repair. Cancellous tissue, or trabecular bone, is the spongy bone found inside bones that contains the marrow but is not a lining tissue like the endosteum.