Other types of cartilage include fibrocartilage, elastic cartilage, and physeal cartilage. Fibrocartilage contains abundant thick bundles of mostly type I collagen which can be seen with the light microscope. This type of cartilage is found at ligament and tendon insertions into bone, in menisci, intervertebral discs, the symphysis pubis, temporomandibular and sternoclavicular joints. Fibrocartilage provides good resistance to shear and compression forces. Elastic cartilage is characterised by the presence of elastic fibres within the matrix which increase elasticity in tissues such as the external ear and trachea.
Physeal cartilage provides longitudinal growth to immature long bones.
Chondroblasts which are derived from mesenchymal cells become trapped in lacunae and develop into chondrocytes. Articular cartilage is a highly hydrated material. Weight bearing capacity is made possible through regional changes in water content which allow deformation of the cartilage surface in response to stress. Water provides nutrition and lubrication of cartilage. GAG's are bound to a protein core by sugar bonds to form a proteoglycan aggrecan molecule.