The five major functions of the skeletal system include supporting the body, storing minerals, producing blood cells, protecting organs and providing movement, according to Cleveland Clinic. Bones maintain body position, produce efficient movements and allow humans to sit, stand and walk.
Cleveland Clinic indicates that bones support the body by attaching to soft tissues, muscles and organs through connective tissues such as ligaments and tendons. Bones also protect vital organs necessary for survival. The skull encases the brain; ribs protect the lungs; the spine keeps the spinal cord intact; and the pelvis protects reproductive organs. Bones move the body by changing the forces and directions generated by muscles.
The skeletal system provides two other important functions that are less obvious. Cleveland Clinic explains that bones store calcium, phosphorus and lipid deposits until the body needs these substances. Lipids are used for energy production and are stored in yellow bone marrow. Red bone marrow makes red blood cells, white blood cells and other essential blood elements deep inside bones. Red blood cells carry oxygen to all parts of the human body, and white blood cells protect against infections, according to the BBC.
Bone growth and the skeleton determine the size and proportions of a body. Cleveland Clinic reveals that bones begin to grow in the womb at about six weeks and continue growing to age 25 in fully grown adults.