which type of collagen is found in bone
Collagen Depending upon the degree of mineralization, collagen tissues may be either rigid (bone) or compliant (tendon) or have a gradient from rigid to compliant (cartilage). It is also abundant in corneas, blood vessels, the gut, intervertebral discs, and the dentin in teeth.[3] In muscle tissue, it serves as a major component of the endomysium. Collagen constitutes one to two percent of muscle tissue and accounts for 6% of the weight of strong, tendinous muscles.[4] The fibroblast is the most common cell that creates collagen. Gelatin, which is used in food and industry, is collagen that has been irreversibly hydrolyzed.[5] Collagen also has many medical uses in treating complications of the bones and skin.
Bone The hard outer layer of bones is composed of cortical bone also called compact bone. Cortical referring to the outer (cortex) layer. The hard outer layer gives bone its smooth, white, and solid appearance, and accounts for 80% of the total bone mass of an adult human skeleton.[citation needed] Cortical bone consists of multiple microscopic columns, each called an osteon. Each column is multiple layers of osteoblasts and osteocytes around a central canal called the haversian canal. Volkmann's canals at right angles connect the osteons together. The columns are metabolically active, and as bone is reabsorbed and created the nature and location of the cells within the osteon will change. Cortical bone is covered by a periosteum on its outer surface, and an endosteum on its inner surface. The endosteum is the boundary between the cortical bone and the cancellous bone. [6]