206 bones connected by 360 joints.

1. Fibrous joints (fixed)- Bones are connected by ligaments.- Sutures: Completely fixed in adults; allows molding during childbirth- Syndesmosis: Joing between radius and ulna in forearm (interosseous membrane)- Gomphosis: Joint between roots of a tooth and its socket (peridontal ligaments)

2. Cartilaginous joints- Surrounded by hyaline cartilage- Synchondrosis: Costochondral joint - Between diaphysis and epiphysis and undergoes ossification- Symphysis: Pelvic bone

3. Synovial joints - Most common- Allow flexion & extension, abduction & adduction, rotation - Joint capsel (outer fibrous capsule and inner synovial membrane), synovial fluid: lubricates