What are the primary anatomical features and physiological actions of the systems for movement and protection of the body?

The skeletal, muscular, and integumentary (skin) systems provide support, allow movement, and protect the body. Without bones and muscles, the body would be like an empty sack of skin, without shape and the ability to move. The skin plays an added, critical role because it protects the body from hazards, prevents fluid loss, and helps control temperature.