Once surrounded, osteoblasts become the maintenance cells called osteocytes . Osteoclasts break down bone matrix and help recycle calcium and repair and reshape bone. Figure 44.15 illustrates the human skeleton. Figure 44.17 illustrates endochondral bone formation in a long bone. In conjunction with muscles, bones work as levers to bring about movement.
Tendons join muscle to bone or muscle to muscle.
Ligaments join bone to bone.