The appendicular skeleton consists of 126 bones, enabling movement and manipulation, and includes the limbs and supportive girdles. The pectoral girdle supports the upper limbs, while the pelvic girdle supports the lower limbs, each comprising fused bones that provide stability and protection for vital organs. The upper extremities contain 60 bones, while the lower extremities include 62 bones, with various structures such as the humerus, femur, and tarsals playing key roles in mobility.