How is the anatomy of joints?

Cartilage facilitates joint function and protects underlying bone by distributing large loads, maintaining low contact stress, reducing friction at the joint. Articular cartilage composition (chondrocytes [maintain matrix] and matrix [collagen II, proteoglycans, give compressibility and elasticity, aggrecan main proteoglycan, central core of GAG chondriton sulfate and keratane sulfate which assocciated with hyaluronic acid, collagen network provides stability and resistance against force] it is 2% cells, 70% liquid and 20% solid) Synovial fluid, synoviocytes, manufactured HA GAG, supply nutrients to avascular articular cartilage, provides viscosity to absorb shock from slow movement, and elasticity to absorb shock from rapid movement.)