ABSTRACT
Collagen is a major component of extracellular matrix of all cartilages as it constitutes approximately one half of the dry weight of the tissue. Based on the histological appearance, cartilage is classified into three types these are as follows hyaline, elastic, and fibrocartilage. Hyaline cartilage is the most common and well-characterized type of cartilage which covers the articular surface of bones and supports tracheal tubes, larynx, and ventral ends of ribs. It provides the embryos with temporary skeletons which are eventually resorbed and replaced by bone. Elastic cartilage is a yellowish opaque tissue found in epiglottis and external ear. It is more flexible than hyaline cartilage, because it contains a high proportion of elastic fibers. Fibrocartilage is a transitional form between hyaline cartilage and fibrous connective tissue. It occurs in meniscus of joints, in annulus fibrosus of intervertebral discs, and in the attachment of tendon to bones.
