Periosteum

The Periosteum is a membrane that covers the outer surface of all bones, except at the joints of long bones. Endosteum lines the inner surface of all bones.

Structure

The periosteum consists of dense irregular connective tissue. It is divided into an outer "fibrous layer" and inner "cambium layer" (or "osteogenic layer"). The fibrous layer contains fibroblasts, while the cambium layer contains progenitor cells that develop into osteoblasts. These osteoblasts are responsible for increasing the width of a long bone and the overall size of the other bone types.

Function

Periosteum, by its very nature, is richly supplied with nerves and blood vessels. This is significant in bone repair; for example, when a bone fracture occurs, the periosteum is the first layer of the bone to start the process of bone repair.

Clinical significance

Damage to the periosteum can cause bones to stop growing in children. In adults, it can lead to uneven bone growth. The periosteum also plays a key role in the healing of bone fractures due to its role in bone repair.

See also

• Endosteum
• Bone tissue
• Osteoblast
• Bone fracture

External links

• Periosteum at Encyclopædia Britannica

Periosteum

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  Periosteum and Endosteum
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  Meninges Diagram
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  Diagram of Compact Bone
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  Periosteum