luukalvon

Luukalvo, also known as periosteum, is a dense layer of connective tissue that covers the outer surface of bones, except for the articular surfaces of synovial joints, which are covered by articular cartilage. It is composed of two layers: an outer fibrous layer and an inner cellular layer. The outer layer is rich in collagen fibers and blood vessels, providing structural support and nourishment to the bone. The inner layer, also called the cambium layer, contains osteoprogenitor cells, which are stem cells that can differentiate into osteoblasts, the cells responsible for bone formation.

The periosteum plays several vital roles in bone health. It is essential for bone growth in thickness, as osteoblasts in the inner layer deposit new bone tissue on the surface. It also contributes to bone repair after fractures; the cambium layer proliferates and differentiates into cells that form the callus, which bridges the gap in the broken bone. Furthermore, the periosteum serves as an attachment point for tendons and ligaments, anchoring muscles to the skeleton. Its rich vascularization provides a blood supply to the outer layers of the bone and contributes to the overall metabolic activity of the skeletal system. In cases of infection, the periosteum can become inflamed, leading to a condition known as periostitis.