Cartilage consists of specialized cells called chondroblasts which secrete matrices containing collagen fibres, well supplied with proteoglean and elastic fibres.  The margin of a piece of cartilage is enclosed by a dense layer of cells and fibrils called perichondrium.
Cartilages unlike bones, are flexible tissues highly adapted to resist any strain that is placed on it. The cartilage matrix is compressible and elastic and it is also able to absorb mechanical shock which occurs frequently between  the surfaces of bones where they meet. They are found in bones of ear, nose, bronchial tubes and bones of unknown baby (foetus). It consist of the following types: hyaline cartilage, yellow elastic cartilage and white fibrous cartilage