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.
https://en.wikipedia.org/wiki/Periosteum
The periosteum serves several functions including anchoring tendons and ligaments, assisting the passage of blood into and out of the bone and assist in growth of the bones. The periosteum is an important part of the skeletal system and is found as a membrane along the outside of the bone.
https://www.reference.com/science/function-periosteum-c76e79bbe59f9be0
The membrane is made up of irregular dense connective tissue, which is divided into two layers called the fibrous layer and the cambium layer. The cambium layer contains the progenitor cells that develop into osteoblast. The osteoblast are key in increasing the width or length of a bone.
https://www.reference.com/science/function-periosteum-c76e79bbe59f9be0
1 Primary bone (woven bone, immature bone) 2  Immature bone that is the first type of bone formed during fetal development, bone repair, and tissue turnover.  Characteristics of primary bone are abundant osteocytes, a low mineral content, and an irregular array of collagen fibers.
http://www.med-ed.virginia.edu/courses/cell/BoneSample/MMHndt_Bone.html
Collagen (mostly Type I) makes up over 90% of the organic component, which is called osteoid. The remainder of organic materials are ground substance proteoglycans and non-collagen molecules involved in the regulation of bone mineralization.
http://www.med-ed.virginia.edu/courses/cell/BoneSample/MMHndt_Bone.html
Types of Bone. 1  Primary bone (woven bone, immature bone) 2  Immature bone that is the first type of bone formed during fetal development, bone repair, and tissue turnover.  Characteristics of primary bone are abundant osteocytes, a low mineral content, and an irregular array of collagen fibers.
http://www.med-ed.virginia.edu/courses/cell/BoneSample/MMHndt_Bone.html
The periosteum consists of an inner osteogenic layer and an outer fibrous layer. 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.
https://en.wikipedia.org/wiki/Periosteum
1 Like other connective tissues, bone consists of cells, fibers, and ground substance but differs because the extracellular matrix is calcified. 2  The rigid extracellular matrix has several functions:  provides an internal support for the body and attachment for muscles and tendons.
http://www.med-ed.virginia.edu/courses/cell/BoneSample/MMHndt_Bone.html
The outer layer of the bone is called the periosteum. This membrane layer of the bone is dense and made up of fibrous tissue. It also consists of nerves and blood vessels that provide blood flow to the bone. Full Answer >.
https://www.reference.com/science/function-periosteum-c76e79bbe59f9be0
1 Osteoprogenitor cells are located in the inner cellular layer of the periosteum, the endosteum and lining osteonic canals.  These cells are most active during bone growth, but large numbers are reactivated in adult life in repair of fractures.
http://www.med-ed.virginia.edu/courses/cell/BoneSample/MMHndt_Bone.html
what makes up periosteum
The periosteum is made of an inner osteogenic layer and an outer fibrous layer. An inner osteogenic layer and an outer fibrous layer makes up periosteum.