Posture Tennis

Improve serve and stroke skills with STEM principles for better performance.

Main Functions of the Skeletal System

It is important to know how the body functions in order to give it a special task to act. The skeletal system is divided into two parts: the axial skeleton and appendicular skeleton. The axial skeleton includes the skull, spinal column, ribs and sternum. The perpendicular skeleton includes all upper and lower extremities, the shoulder girdle and the pelvic girdle. Bones in the human body come in four main shapes, long, short, flat and irregular and are composed of webs of collagen fibers reinforced with calcium and phosphorus. The collagen provides flexibility while the minerals provide tensile strength.

Like the steel framework of a building, the function of the skeleton and the bones is to provide rigidity, which gives the body shape and supports the weight of the muscles and organs. Without this structure, the body would collapse in by itself, compressing the lungs, heart and other organs–impairing their functions. The rigid structure of the skeletal system also allows it to perform another one of the 5 functions of the skeletal system: movement.

The forces from skeletal muscle can control the bone’s movements. When your brain tells some parts of the body to move, some muscles will contract to act — muscles shorten and pull bones to act across joints. Muscles work in pairs — when one shortens, a corresponding muscle lengthens. Physical activity maintains or increases the strength of skeletal muscles. Remember, it is the muscles’ pulling forces that create the body’s movement, not others. Only skeletal muscles work with bones and muscles keep bones in place and also play a role in the movement of bones.

When the muscle contracts, one of the structures usually remains stationary, while the other moves. When muscles contract, the force of muscle contraction is applied to bones, resulting in movement of those bones.