What is the Periosteum?
The periosteum is a tough, fibrous membrane that covers the outer surface of most bones, excluding the areas within joint spaces (articular surfaces). Think of it as a protective sleeve for your bones.
The periosteum is composed of two distinct layers:
- Outer Fibrous Layer: This layer is dense and irregular, providing structural support and protection to the underlying bone. It's primarily made of collagen fibers.
- Inner Cellular Layer (Cambium Layer): This layer is thinner and contains osteoblasts, the cells responsible for bone formation (osteogenesis). This layer is crucial for bone growth and repair.
Function
The periosteum plays several vital roles:
- Bone Nourishment: It houses a rich network of blood vessels and nerves that supply the bone with nutrients and sensation. This is essential for bone health and maintenance.
- Bone Growth and Repair: The inner cellular layer's osteoblasts facilitate bone growth during development and repair fractures.
- Bone Attachment: It serves as an attachment point for tendons and ligaments, enabling movement and stability of the skeleton.
Thickness and Age
The periosteum is typically thicker in younger individuals and gradually thins as bones mature.
Clinical Significance
Damage to the periosteum, such as from injury or disease, can impair bone healing and cause pain. Conditions affecting the periosteum include periostitis (inflammation) and periosteal chondromas (benign tumors).
References: The information presented here is consolidated from various sources including MedlinePlus, Cleveland Clinic, Britannica, and PubMed articles on the periosteum. These sources consistently describe the periosteum's structure, function, and clinical relevance. Specific citations are not provided inline for brevity, but all information is supported by the provided references.
