Video - Cartilage histology

Cartilage is a unique connective tissue in that it is smooth, elastic, and lacks blood vessels. Its primary function is to provide cushioning and support for the body's joints and other structures, such as the C-shaped rings supporting the trachea. The matrix of cartilage is composed of collagen fibers and proteoglycans, which are highly charged proteins that bind to water. This combination of collagen and proteoglycans gives cartilage its characteristic spongy texture.

Note that there are three types of cartilage. There is hyaline cartilage characterized by an extracellular matrix with a "glassy" appearance. hyaline cartilage is found in the trachea and the articulating surfaces of the long bones. Second is the elastic cartilage, characterized by a dense network of elastic fibers. Elastic cartilage is commonly found in the epiglottis and the pina of the external ear.

Finally, there is fibrocartilage which is a combination of hyaline cartilage and dense connective tissue. This one is found in the knee meniscus and the intervertebral discs. Over time, cartilage can break down due to wear and tear injury or disease. When this happens, the affected joint may become painful and stiff, and in severe cases, the joint may no longer be able to move properly.