Not all of the cartilage of mammals is replaced, however. Some of it persists in areas which require resilient but flexible stiffening. Examples include the walls of larger respiratory passageways, the tip of the nose, and the ears.
Cartilage is also present at the articular surfaces of joints.
Elastic cartilage and fibrous cartilage are the other two. Many authorities regard the last as a transitional form between cartilage and connective tissue proper. As with all CT's, cartilage is a combination of cells, fibers, and intercellular matrix material. The fibrillar components provide for shape retention and tensile strength, while the viscous, hydrated matrix absorbs compression forces. In the case of hyaline cartilage, the matrix material is the predominant element.