Answer
The periosteum is a layer of tissue that covers bones where articular cartilage is missing. Structurally it is a complex covering and serves may purposes:
The following are some of the important functions of the periosteum;
1. The bone grows in thickness by the mitotic activity of the inner osteogenic layer of the
periosteum
2. The periosteum offers some protection to the bone .
3. The mitotic activities of periosteal osteogenic cells promote healing of bone fractures
4. The periosteum has a good vascular supply which usually nourishes the superficial layers of the
cortex of bones. Periosteal arteries also act as an axillary vascular supply in case of
blockage of arteries in other bone blood supply sources.
5.The outer periosteal layer provides important points of attachment for ligaments and tendons.
Work Step by Step
The periosteum is is a connective tissue layer that covers the surfaces of bones, except where articular cartilage is present. Periosteal coverings are double-layered: the outer layer is made up largely of tough irregular connective tissue, while the inner layer that makes contact with bone tissue is more cellular and vascular-- and has more elastic fibers.
The periosteum protects the bone in several ways: it is a physical and a chemical barrier, as well as
a defence against penetration by microbes.
The mitotic activity of cells of the inner osteogenic layer of the periosteum is responsible for bone growth in thickness--but not in length.
The blood vessels of the periosteum constitute one of the three sources of blood in long bones.. Ordinarily, they nourish the superficial layers of the cortex of the bone matrix; however, they also constitute a back-up resource, if there is a blockage in vessels in either of the two blood sources that supply bones.
Perioustem promotes healing of bone fractures and provides points of attachment for tendons and ligaments. In addition, it should be remembered that the not only blood vessels, but also nerves that serve bones, travel through periosteum .
