The periosteum

Introduction

The periosteum is a thin layer of cells that surrounds the entire bone up to the limits of the joint surfaces covered with cartilage. The good blood supply to the bone enables regeneration. The periosteum can be divided into two layers, whose tasks are to anchor the skin to the bone surface, to nourish the skin and to heal fractures. Injuries and inflammation of the periosteum can cause pain in the context of fractures or overloading.

What is the periosteum?

The periosteum is called periosteum in the technical language. It consists of a thin layer of cells that surrounds every bone in the human body. This includes the entire bone with the exception of the joint surfaces, which are covered by cartilage.

The periosteum also includes the parts of the tendons and ligaments that are close to the bone. In contrast to the cell layer on the outer surface, the cell layer on the inner surface of the bone is called the endost. The tissue is well supplied with blood and therefore rich in oxygen and nutrients. This serves the bone for regeneration and nutrition.

The anatomy of the periosteum

The periosteum consists of two cell layers with several cell layers per layer. The outer layer is always closer to the skin than the inner layer at every point of the bone. The outer cell layer is also called stratum fibrosum in technical terminology.

The inner layer is sometimes called stratum osteogenicum. As the name of the stratum fibrosum indicates, the outer cell layer has a high proportion of fibers. These fibers pass through the layer.

More precisely, this means that the stratum fibrosum has a large amount of collagen fibers, which give this cell layer a high degree of stability. The collagen fibers are also called Sharpey fibers, which also occur on the teeth. In addition to the outer cell layer, the Sharpey fibers also penetrate the inner stratum osteogenicum and end up in the bone substance.

The tissue or cells that form the collagen fibers mentioned are assigned to the connective tissue. Furthermore, the fluid surrounding the cells is formed by this connective tissue. In contrast to the outer layer, the inner stratum osteogenicum is rich in cells and even contains stem cells.

These stem cells play an important role in the continuous remodelling of the bone or the regeneration of the bone, for example in the case of a fracture. In addition to these cells, nerves and blood vessels are also found in the inner cell layer. These are essential for the nutrition and regeneration of the bone.