Cartilage Properties of Cartilage Matrix Chondrocytes 1. Avascular Fibers (collagen Type II, 2. Permeable Fibers elastic) (conducts nutirents and water) Ground Substance 3. Flexible but Weight-Bearing (hyaluronic acid, (resistance to compression) chondroitin sulfate, keritin sulfate, 4. Elasticity and Resiliency 60-70% H2O) 5. Resistance to Shear Forces 6. Slippery (low friction at articular joints) Isogenous 7. Poor Regenerative Capacity Lacunae Group

Hyaline Cartilage Hyaline Cartilage Matrix (amorphous & glassy) hyaluronic acid chondroitin sulfate keratin sulfate chondrocyte nucleus H2O (60-78%) lacuna Fibers- collagenous matrix (invisible due to same refractive index as matrix) Typical Locations Hyaline Cartilage (SEM) intercostals (connect ribs to the sternum) wall of trachea & bronchii articular cartilage of bone epiphyseal plate fetal axial skeleton

Fibrocartilage Matrix hyaluronic acid chondroitin sulfate Fibrocartilage- longitudinal section Matrix collagenous fiber bundles hyaluronic acid Fibrocartilage- SEM chondroitin sulfate keratin sulfate Fibers dense collagenous bundles Typical Locations intervertebral discs Fibrocartilage- transverse section pubic symphysis meniscus of knee joint attach tendons to bone Properties resistance to compression and shear forces

Elastic Cartilage Elastic Cartilage- pinnae of ear Elastic Fibers Matrix (resorcin-fuchsin stain) hyaluronic acid chondroitin sulfate kertatin sulfate Fibers elastic (elastin) Typical Locations external ear walls of external auditory canal and eustachian tubes Elastic Fibers- silver stain epiglottis & larynx bridge of nose Properties resiliency and pliability

Growth of Cartilage fibroblasts collagen Perichondrium perichondrium Appositional blood vessel Growth chondroblasts (peripheral mitosis and differentiation of fibroblasts) hyaline matrix Interstitial Growth isogenous (mitosis of chondro- groups cytes and deposition (nests of of new matrix) chondrocytes) Territorial Matrix