Humans have organ systems which work together to keep us alive. The function of an organ system depends the activities of organs involve in that system. For example, muscular system organs integrate themselves to bring about movement of the body.
Bones and muscles are the organs of the muscular system. They work together by receiving impulses and signals from the brain. In order to move, the nervous system then sends signals a skeletal muscle to contract. When the muscles contract, the attached bone works accordingly.