1. The Muscular System Class #1

2. Functions of the Muscular System What comes to mind when you think of muscles?

3. Functions of the Muscular System Maybe you think about the muscles in your arms or legs that enable you to carry books or run fast. Movement is an important function of the muscular system.

4. Functions of the Muscular System But muscles are also important for protection, stability, and maintaining body temperature.

5. Functions of the Muscular System Although muscles have different functions, all muscle tissues are made of cells that contract.

6. Functions of the Muscular System A muscle is made of strong tissue that can contract in an orderly way.

7. Functions of the Muscular System When a muscle contracts, the cells of the muscle become shorter, as shown in figure 9. When a muscle relaxes, the cells return to their regular length.

8. Stability Muscles that are attached to bones support your body and help you balance.

9. Stability If your body becomes unstable, such as when you trip and lose your balance, your muscles pull in different directions and you regain your balance.

10. Stability Tendons attach muscles to bones, as shown in Figure 10.

11. Stability Look at the back of your hand and move your fingers. Do you see cordlike structures moving under your skin? These are tendons.

12. Stability You can feel the Achilles tendon above either of your heels. Tendons also help hold your body in a proper posture, or shape.

13. Protection Muscles protect your body. As shown in figure 11, muscles cover most of your skeleton.

14. Protection Muscles also cover most of the organs inside your body.

15. Protection Muscles are like a layer of padding. They surround your abdomen, chest, and back and protect your internal organs.

16. Temperature Regulation Have you ever been in a cold environment and started shivering?

17. Temperature Regulation Shivering is when muscles contract rapidly and change chemical energy to thermal energy.

18. Temperature Regulation The thermal energy helps raise your body’s temperature. This is important because a human’s body temperature must stay around 37 C in order for the body to function properly.

19. Temperature Regulation Muscles also change chemical energy to thermal energy during exercise. This is why you feel warm after physical activity.

20. Types of Muscle Your body has three different types of muscles: skeletal, cardiac, and smooth. Each of these muscle tissues is specialized for a different function.

21. Homework The Muscular System:_______ Muscles:__________________ Protection:_______________ Stability:_________________ Body temperature:_________ Muscle cell:_______________ Contract:_________________ Regain balance:____________ Tendons:__________________ Cord Like Structures:________ Proper Posture:____________ Achilles Tendon:____________ Translate the words into Chinese and then send me a WeChat message saying the words in English Name:____________ Internal Organs:______________ Abdomen:__________________ Shivering:__________________ Chemical Energy:_____________ Thermal Energy:______________ Body Temperature:___________ Physical Activity:_____________ Skeletal Muscles:_____________ Cardiac Muscles:_____________ Smooth Muscles:_____________ Tendons attach muscles to bones:_____________________ All muscle tissues are made of cells that contract: ___________ ___________________________

22. With a Partner, try to answer the True or False Questions 1. Muscle cells cannot contract. 2. Muscles are made of weak tissue. 3. Tendons attach muscles to bones. 4. Tendons don’t help your body maintain it’s structure. 5. Muscles cover most of your skeleton 6. Muscles protect your internal organs 10. Your body has four types of muscles 7. Your muscles change chemical energy into thermal energy 8. Exercise lowers your bodies temperature 9. Your muscles don’t help regulate your temperature 1. True/ False 2. True/ False 3. True/ False 4. True/ False 5. True/ False 6. True/ False 7. True/ False 10. True/ False 9. True/ False 8. True/ False

23. With a Partner, try to answer the True or False Questions 1. Muscle cells cannot contract. 2. Muscles are made of weak tissue. 3. Tendons attach muscles to bones. 4. Tendons don’t help your body maintain it’s structure. 5. Muscles cover most of your skeleton 6. Muscles protect your internal organs 10. Your body has four types of muscles 7. Your muscles change chemical energy into thermal energy 8. Exercise lowers your bodies temperature 9. Your muscles don’t help regulate your temperature 1. True/ False 2. True/ False 3. True/ False 4. True/ False 5. True/ False 6. True/ False 7. True/ False 10. True/ False 9. True/ False 8. True/ False