Show the diagram of muscle cells and go through the muscle fiber, the myofibril, and sarcomere. Explain that muscles move by contracting and then relaxing. Introduce the three types of muscle tissue: skeletal, cardiac, and smooth, briefly describing each. Explain each one in detail, beginning with smooth muscle. Students spin the wheel and describe how smooth muscle works in the body. Next, explain the function of cardiac muscle and then move on to skeletal muscle. Have students lift an object and observe how their bicep activates. Then have them drag the muscle type to the correct location on the diagram. Get students moving by having them stand on their toes and then squat. Can they feel their muscles working? Explain that these large muscles are powerful. Exercising can ensure that these muscles stay strong and healthy later in life. Finally, show students each of the major muscle groups.