The human skeleton is the internal framework of the body. It is made up of about 300 bones at birth. As some bones join together, there are 206 bones in adulthood. The bones are at their strongest around age 20. The human skeleton can be divided into the "axial skeleton" and the "appendicular skeleton". The axial skeleton is formed by the vertebral column, the rib cage, the skull and other associated bones. The appendicular skeleton, which is attached to the axial skeleton, is formed by the shoulder girdle, the pelvic girdle and the bones of the upper and lower limbs.