Cartilage is firm, solid, and resilient. It is composed of cells (chondrocytes), fibers (type II collagen), and a firm, gel-like ground substance. Cartilage has very few blood vessels and nerves within, but the covering perichondrium supplies vascular needs and contains stem-like cells that will differentiate into new cartilage cells. Depending on the composition of the ground substance, nutrients and oxygen can percolate into the tissue