What does the periosteum contain?
Periosteum consists of dense irregular connective tissue. Periosteum 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. After a bone fracture the progenitor cells develop into osteoblasts and chondroblasts, which are essential to the healing process.
While most tissues have a Endo, Peri, and Epi covering. Bone simply has an endosteum and periosteum. Some older texts will refer to the periosteum as an epiosteum. The periosteum is found enveloping bones with the exception of the articulating joints. The periosteum contains a fibrous outer layer and a cellular inner layer containing progenitor cells.
The periosteum is a layer of connective tissue and bone cell precursors that overlies the bone itself. Excess growth between the periostem and bone can cause the periosteum to separate from the underlying bone. This elevation of periosteum forms a triangular shape when viewed in a radiograph (xray), and is often called Codman's triangle. Periosteal elevation is commonly associated with a cancer called osteosarcoma, but may also be seen in other diseases.