B. Elastic Cartilage:

ØElastic cartilage is yellowish when fresh. It is more Rexible than hyaline cartilage .

Ø1. Composition and organization. Elastic cartilage is structurally identical to hyaline cartilage except that it contains, in addition to type II collagen fibers, a dense network of branching and anastomosing elastic fibers. This network is densest at the core of the cartilage mass and when stained with elastic stains tee, Verhoeff's or Weigert's), may obscure the organization of the tissue. The chondrocytes characteristically occur in isogenous groups. A perichondrium surrounds the elastic cartilage mass.

Ø2. Histogenesis and growth, Elastic cartilage develops from a primitive connective tissue containing wavy bundles of fibrils that differ in protein composition from both elastin and collagen. Fibroblasts eventually secrete elastin, and the fiber bundles are transformed into branching elastic fibers by an unknown mechanism. The development of chondrocytes and production of the other matrix materials is the same as in hyaline cartilage. Further growth resembles that of hyaline cartilage. 3. Function and location. Elastic cartilage provides flexible support. It occurs alone and with hyaline cartilage; the two may grade into each other in a single cartilage mass. In humans, elastic cartilage is found in the auricle of the external ear, the walls of the external auditory canals and auditory tubes, the epiglonis, and the corniculate and cuneiform cartilages of the larynx.