The skeletal and muscular systems work together to help the body move. The skeletal system is made up of bones that support the body, give it shape, and protect organs. Muscles move the body by contracting and relaxing. There are three types of muscles - skeletal, smooth, and cardiac. Skeletal muscles move bones and allow voluntary movement. Smooth muscles line organs and blood vessels and work involuntarily. Cardiac muscle makes up the heart and contracts rhythmically without stopping.

1. The Skeletal and Muscular Systems