Skeletal muscles, also known as striped, striated, somatic or voluntary muscles, are attached to the skeleton. They respond quickly to stimuli and allow for fast contractions but also fatigue easily. Skeletal muscles give the body its shape and structure, as without the skeletal structure the body would have no form. The human skeletal system consists of the axial skeleton and appendicular skeleton, with the axial skeleton made up of 80 bones that protect organs and maintain an upright structure, while the appendicular skeleton has 126 bones attached to the axial skeleton that allow for movement and protect other organs.