CARTILAGE

A cartilage is a tough elastic and semitransparent tissue devoid of blood vessels and nerves.

Functions of cartilage

1. It prevents friction between two bones and allows smooth and free movement.
2. It absorbs shock between bones. For example the shock resulting from the vertebral bones are absorbed by cartilaginous intervertebral discs.
3. It keeps open the trachea (windpipe) so that air flows into the lungs always. The cartilage of the nose also keeps the nostrils open for in-take of fresh air and output of waste air.
4. The cartilage of the ribs allows contraction and expansion of the thorax thus enhancing breathing mechanism.
5. It forms cushion in the sockets of bones such as the glenoid cavity of the shoulder and hip sockets.
6. The ear cartilage keeps the pinnae (external ear) erect so as to collect sound vibrations from the air.
7. Cartilage and bone provide the firm areas for attachment of the tendons of the muscles.
8. Fibro-cartilage is found in the pubis symphysis where it allows for considerable expansion of the pubis during parturition (child birth) without complete breakage.