<P> Collagen / ˈkɒlədʒɪn / is the main structural protein in the extracellular space in the various connective tissues in animal bodies . As the main component of connective tissue, it is the most abundant protein in mammals, making 25% to 35% of the whole - body protein content . Collagen consists of amino acids wound together to form triple - helices to form of elongated fibrils . It is mostly found in fibrous tissues such as tendons, ligaments and skin . </P> <P> 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 . 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 . 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 . Collagen also has many medical uses in treating complications of the bones and skin . </P>

Where are collagen fibers found in the body