The BBC explains that the skeletal system’s main functions include providing shape, support and protection for the body. Additionally, in conjunction with the muscular system, it allows the body to move in a coordinated fashion. The various bones of the body serve different purposes and they have evolved different characteristics, such as differing sizes, shapes and densities, which allow them to perform such jobs.
Protection is the primary job of the skull and ribs, according to the BBC. Accordingly, the skull takes more pressure to break than most other types of bone in the body, excluding the femur. The entire skeleton helps to provide the shape of the body. The human skeleton serves as a framework for the attachment of muscles, connective tissues and skin. These attached muscles and tissues help fill in the overall shape of the body, but they also pull on the skeleton to achieve movement.
The axial skeleton, which is composed of the vertebral column, ribs and skull, supports the weight of the body, according to LiveScience. The appendicular skeleton includes the bones that attach to the axial skeleton and they permit movement.
According to LiveScience, the number of bones in the human body changes over time. Infants have between 300 and 350 different bones. However, as they mature, many of these bones fuse. Most humans have only 206 bones by the time they reach the age of 9.