Defends the body after it has been invaded by a microscopic organism. endocrine system 2. regulates the body's metabolism, growth, and functions of the sexual organs. skeletal system 3. protects the internal tissues of the body from potential harm. reproductive system 4. responsible for conception. circulatory system 5. provides the body with a framework that is strong and mobile muscular system 6. consists of 600 skeletal muscles that allow the body to move. immune system 7. carries life-giving blood to the cells. integumentary system next question ask for