What is the periosteum?

The periosteum is a fibrous membrane that covers the surface of bones. This outer layer serves several essential functions, including providing a protective covering for the bone, serving as an attachment point for muscles and tendons, and playing a critical role in the healing process following bone injuries.

The periosteum consists of two layers: an outer fibrous layer made of dense connective tissue, which helps secure the periosteum to the bone, and an inner cambium layer, which contains osteoblasts that are important for bone growth and repair. The rich supply of blood vessels and nerve fibers in the periosteum also contributes to the nourishment of the bone and the sensation of pain in case of injury.

The other options describe different structures and functions that do not relate to the periosteum. Cartilage is a smooth tissue found in joints, fluid-filled sacs in joints (bursae) help reduce friction, and the primary ossification center is related to the development of bones, but these all serve different roles within the musculoskeletal system.