1. Chapter 13 Bones and Muscles Table of Contents Chapter Preview 13.1 Organ Systems and Homeostasis 13.2 The Skeletal System 13.3 The Muscular System 13.4 Machines and the Body

2. Chapter 13 Bones and Muscles Chapter Preview Questions 1. The position of an object can be changed by a. pushing on the object. b. pulling on the object. c. pushing or pulling on the object. d. measuring the object’s weight.

3. Chapter 13 Bones and Muscles Chapter Preview Questions 1. The position of an object can be changed by a. pushing on the object. b. pulling on the object. c. pushing or pulling on the object. d. measuring the object’s weight.

4. Chapter 13 Bones and Muscles Chapter Preview Questions 2. The magnitude of a force is the same as a. its strength. b. its direction. c. the distance the force moves an object. d. friction produced by the force.

5. Chapter 13 Bones and Muscles Chapter Preview Questions 2. The magnitude of a force is the same as a. its strength. b. its direction. c. the distance the force moves an object. d. friction produced by the force.

6. Chapter 13 Bones and Muscles Chapter Preview Questions 3. The bigger the change in an object’s motion, the a. smaller the push or pull required. b. bigger the push or pull required. c. more likely the object will move in more than one direction. d. more likely the object will stop moving.

7. Chapter 13 Bones and Muscles Chapter Preview Questions 3. The bigger the change in an object’s motion, the a. smaller the push or pull required. b. bigger the push or pull required. c. more likely the object will move in more than one direction. d. more likely the object will stop moving.

8. Chapter 13 Bones and Muscles Chapter Preview Questions 4. When you use your foot to stop a rolling ball, you are a. pulling on the ball. b. pushing on the ball. c. changing the direction in which the ball rolls. d. changing the force that started the ball rolling.

9. Chapter 13 Bones and Muscles Chapter Preview Questions 4. When you use your foot to stop a rolling ball, you are a. pulling on the ball. b. pushing on the ball. c. changing the direction in which the ball rolls. d. changing the force that started the ball rolling.

10. Chapter 13 Bones and Muscles A cat sleeps on one end of a seesaw, while a mouse crouches on the other end. The cat wakes up and walks away. How will the forces acting on the ends change? How will the forces change if the cat runs across the board toward the mouse? How do the physical principles of forces and machines relate to the functions of your muscles and skeleton?

11. Chapter 13 Bones and Muscles Latin Word Origins Latin WordMeaning of Latin WordKey Term in- not involuntary muscle Type of muscle that is not under a person’s conscious control

12. Chapter 13 Bones and Muscles Latin WordMeaning of Latin WordKey Term ligare to tie ligament Connective tissue that holds bones together Latin Word Origins

13. Chapter 13 Bones and Muscles Latin WordMeaning of Latin WordKey Term porus a tiny opening or hole osteoporosis A condition in which bones lose minerals, develop larger openings than normal bones, and become weak Latin Word Origins

14. Chapter 13 Bones and Muscles Latin WordMeaning of Latin WordKey Term resistere to place against resistance force The force that a lever exerts against an object Latin Word Origins

15. Chapter 13 Bones and Muscles Latin WordMeaning of Latin WordKey Term voluntas free will voluntary muscle Type of muscle that is under a person’s conscious control Latin Word Origins

16. Chapter 13 Bones and Muscles Apply It! 1. How does the meaning of the Latin word ligere help you to understand what a ligament is? Ligare means to tie and a ligament holds bones together. 2. What two key terms in the table come from the Latin word voluntas? What does this Latin word mean? Voluntary muscle and involuntary muscle. It means free will.

17. Chapter 13 Bones and Muscles End of Chapter Preview

18. Chapter 13 Bones and Muscles Section 1: Organ Systems and Homeostasis What are the levels of organization in the body? What systems are in the human body, and what are their functions? What is homeostasis?

19. Chapter 13 Bones and Muscles The Epidermis In some ways, the skin is the body’s largest organ.

20. Chapter 13 Bones and Muscles Organs and Organ Systems Each organ in your body is part of an organ system, which is a group of organs that work together to perform a major function.

21. Chapter 13 Bones and Muscles Cell Specialization Click the Video button to watch a movie about cell specialization.

22. Chapter 13 Bones and Muscles Links on Body Systems Click the SciLinks button for links on body systems.

23. Chapter 13 Bones and Muscles End of Section: Organ Systems and Homeostasis

24. Chapter 13 Bones and Muscles Section 2: The Skeletal System What are the functions of the skeleton? What role do joints play in the body? What are the characteristics of bone, and how can you keep your bones strong and healthy?

25. Chapter 13 Bones and Muscles What the Skeletal System Does Your skeleton has five major functions. It provides shape and support, enables you to move, protects your organs, produces blood cells, and stores minerals and other materials until your body needs them.

26. Chapter 13 Bones and Muscles Joints of the Skeleton A joint is a place in the body where two bones come together. Joints allow bones to move in different ways.

27. Chapter 13 Bones and Muscles Movable Joints Activity Click the Active Art button to open a browser window and access Active Art about movable joints.

28. Chapter 13 Bones and Muscles Bones—Strong and Living Bones are complex living structures that undergo growth and development.

29. Chapter 13 Bones and Muscles End of Section: The Skeletal System

30. Chapter 13 Bones and Muscles Section 3: The Muscular System What types of muscles are found in the body? Why do skeletal muscles work in groups?

31. Chapter 13 Bones and Muscles Types of Muscles Your body has three types of muscle tissue: skeletal muscle, smooth muscle, and cardiac muscle.

32. Chapter 13 Bones and Muscles Muscles at Work Because muscle cells can only contract, not extend, skeletal muscles must work in pairs. While one muscle contracts, the other muscle in the pair relaxes to its original length.

33. Chapter 13 Bones and Muscles More on Muscle Types Click the PHSchool.com button for an activity about muscle types.

34. Chapter 13 Bones and Muscles Skeletal Muscles Click the Video button to watch a movie about skeletal muscles.

35. Chapter 13 Bones and Muscles End of Section: The Muscular System

36. Chapter 13 Bones and Muscles Section 4: Machines and the Body How are force and work related? How does a lever make work easier? How do bones and muscles function as levers in the body?

37. Chapter 13 Bones and Muscles Force and Work A lever is a simple machine that makes lifting heavy objects easier.

38. Chapter 13 Bones and Muscles Levers A lever is a ridged bar that is free to pivot, or rotate, on a fixed point.

39. Chapter 13 Bones and Muscles Levers Levers are classified according to the location of the fulcrum relative to the input and output forces.

40. Chapter 13 Bones and Muscles Mechanical Advantage The input force and output force for three different ramps are shown in the graph.

41. Chapter 13 Bones and Muscles Mechanical Advantage Input force Reading Graphs: What variable is plotted on the horizontal axis?

42. Chapter 13 Bones and Muscles Mechanical Advantage 400 N Interpreting Data: If an 80-N input force is exerted on Ramp 2, what is the output force?

43. Chapter 13 Bones and Muscles Mechanical Advantage 5 Calculating: Calculate the mechanical advantage of Lever 2.

44. Chapter 13 Bones and Muscles Mechanical Advantage Lever 1 produces the greatest resistance force in each case because it has the greatest mechanical advantage. Drawing Conclusions: Which lever produces the greatest resistance force when an effort force of 20N is exerted? Which lever has the greatest mechanical advantage?

45. Chapter 13 Bones and Muscles Simple Machines in the Body Most of the machines in your body are levers that consist of bones and muscles.

46. Chapter 13 Bones and Muscles Links on Work Click the SciLinks button for links on work.

47. Chapter 13 Bones and Muscles Levers Click the Video button to watch a movie about levers.

48. Chapter 13 Bones and Muscles End of Section: Machines and the Body

49. Chapter 13 Bones and Muscles QuickTake Quiz Click to start quiz.