Overview

Hyaline cartilage has an abundant matrix and many chondrocytes located in small spaces within the matrix called lacunae.  Chondrocytes divide within their lacunae forming isogenous groups of cells, and disperse as each secretes matrix around themselves.  Matrix fibers, composed of Type II collagen, are quite thin and not resolved by light microscopy.  Hyaline cartilage is found in the nose, larynx, trachea, and forms articular cartilages at then ends of bones.

Elastic cartilage is more cellular than hyaline cartilage with fewer isogenous groups. The most obvious feature of elastic cartilage is the abundant elastic fibers component of the matrix.  These fibers impart great flexibility to the matrix. Elastic cartilage is found in the external ear, the epiglottis and some of the minor laryngeal cartilages.

Fibrocartilage does not exist as an independent cartilage, but rather is a mixture of hyaline cartilage and dense connective tissue. Chondrocytes and their surrounding matrix are aligned between bundles of Type I collagen fibers. Due to its structure, fibrocartilage acts as a shock absorber, resisting both sheering and compressional forces. Fibrocartilage is found in intervertebral discs, pubic symphysis, knee cartilages (menisci) and between tendons and their bony insertions.