Cartilage can be found in the human body both around joints as well as in certain hard but not inflexible areas of the body, like the nose and the ear. Joints with cartilage include the rib cage, the elbow, and, in the legs, the knees and ankles. Cartilage is hard, but not so rigid as bone matter. Instead, it is somewhat flexible, albeit less so than the much less dense muscle tissue. Thus cartilage can play a structural function in certain areas, like the nose, but cannot perform this function to the same extent as dense bones do. Cartilage is made up of a special type of cell called the chondrocyte, as well as two materials produced by the chondrocytes, collagen fibers and elastic fibers. There are different types of cartilage, characterized by the differing ratios of fibers contained within them. In addition, cartilage is the only connective tissue in the human body which is not exposed to the blood circulation via its own network of arteries or veins. Instead, blood and nutrients diffuse through the cartilage to the extent that they are pushed through the material by movement and pumping action. This makes cartilage the slowest tissue to grow and, when damaged, the slowest to repair itself.
Bones can be found throughout the human body as basic structural components providing form to the body and protecting internal organs such as the rib cage. The human body contains 206 bones, and more in