Three Kinds of CartilageCartilage, unlike other types of connective tissue, has no blood vessels. It is tough but pliant because the ground substance between the cells contains combinations of proteins and sugars. Cartilage is described as hyaline, fibrous or elastic, depending on the density and type of fibers present in its composition. Hyaline, the most abundant type of cartilage, is clear and glassy, with few cells and fibers in the ground substance. Hyaline covers the ends of bones at the joints, and also forms the rings which keep the trachea open. Fibrocartilage is made up of tightly packed bundles of collagen fibers, making it resilient and able to withstand compression. Fibrocartilage lies, for example, between vertebrae. Elastic cartilage contains, in addition to collagen, fibers of the protein elastin. This makes it firm yet supple, giving support, for example, to the external ear and epiglottis.