Cartilage as the cricoid cartilage and carina. Cartilage is composed of specialized cells called chondrocytes that produce a large amount of collagenous extracellular matrix, abundant ground substance that is rich in proteoglycan and elastin fibers. Cartilage is classified in three types, "elastic cartilage", "hyaline cartilage" and "fibrocartilage", which differ in relative amounts of collagen and proteoglycan. Cartilage does not contain blood vessels (it is avascular) or nerves (it is aneural). Nutrition is supplied to the chondrocytes by diffusion. The compression of the articular cartilage or flexion of the elastic cartilage generates fluid flow, which assists diffusion of nutrients to the chondrocytes.
Articular cartilage damage fill in articular cartilage defects, its structure is significantly different from that of hyaline cartilage; it is much denser and it doesn't withstand the demands of everyday activities as much as hyaline cartilage. It is therefore at a higher risk of breaking down. Wang "et al."(2006) found that small articular cartilage defects can progress to osteoarthritis over time if left untreated. An articular cartilage defect that initially may be small still has the potential to have a physical and chemical "domino effect" on the surrounding "normal" articular cartilage. Though articular cartilage damage is not life-threatening, it does strongly affect one's