The document describes the process of breathing and gas exchange in the human body. It explains how oxygen from the air passes through the trachea and bronchi into the lungs, where it diffuses across the alveoli into blood vessels. Meanwhile, carbon dioxide diffuses from the bloodstream into the alveoli to be exhaled. It also outlines the role of the diaphragm and intercostal muscles in inhaling to expand the lungs and exhaling to contract the lungs during breathing.

1. HEALTH & EXERCISE Module 8

2. Breathing and Gas Exchange

3. The Human Thorax How the structure of the thorax enable ventilation of the lungs and gas exchange. Trachea, cartilage rings, bronchi, bronchioles, alveoli, diaphragm, ribs, intercostal muscles

5. Trachea

6. Trachea – surrounded by cartilage rings that keep the tube open

8. Trachea – surrounded by cartilage rings that keep the tube open Left lung

9. Trachea – surrounded by cartilage rings that keep the tube open Left lung Left bronchus, the major division of the trachea as it enters the lungs

11. Trachea – surrounded by cartilage rings that keep the tube open Left lung Left bronchus, the major division of the trachea as it enters the lungs Bronchiole – a smaller branch off the larger bronchus

13. Trachea – surrounded by cartilage rings that keep the tube open Left lung Left bronchus, the major division of the trachea as it enters the lungs Bronchiole – a smaller branch off the larger bronchus Heart – responsible for pumping blood around the body

15. Trachea – surrounded by cartilage rings that keep the tube open Left lung Left bronchus, the major division of the trachea as it enters the lungs Bronchiole – a smaller branch off the larger bronchus Heart – responsible for pumping blood around the body Rib – provides protection for lungs and heart

17. Trachea – surrounded by cartilage rings that keep the tube open Left lung Left bronchus, the major division of the trachea as it enters the lungs Bronchiole – a smaller branch off the larger bronchus Heart – responsible for pumping blood around the body Rib – provides protection for lungs and heart Right lung

18. Trachea – surrounded by cartilage rings that keep the tube open Left lung Left bronchus, the major division of the trachea as it enters the lungs Bronchiole – a smaller branch off the larger bronchus Heart – responsible for pumping blood around the body Rib – provides protection for lungs and heart Right lung Right bronchus

19. Trachea – surrounded by cartilage rings that keep the tube open Left lung Left bronchus, the major division of the trachea as it enters the lungs Bronchiole – a smaller branch off the larger bronchus Heart – responsible for pumping blood around the body Rib – provides protection for lungs and heart Right lung Right bronchus Alveoli (air sacs), site of gas exchange

21. Trachea – surrounded by cartilage rings that keep the tube open Left lung Left bronchus, the major division of the trachea as it enters the lungs Bronchiole – a smaller branch off the larger bronchus Heart – responsible for pumping blood around the body Rib – provides protection for lungs and heart Right lung Right bronchus Alveoli (air sacs), site of gas exchange Intercostal muscles lift ribs up & out

23. Gas Exchange in the alveoli

24. Gas Exchange in the alveoli Oxygen from the air in the alveoli diffuses into the blood. At the same time, carbon dioxide from the blood diffuses into the alveoli.

25. Gas Exchange in the alveoli Oxygen from the air in the alveoli diffuses into the blood. At the same time, carbon dioxide from the blood diffuses into the alveoli. Oxygen dissolves in the moist lining

26. Gas Exchange in the alveoli Oxygen from the air in the alveoli diffuses into the blood. At the same time, carbon dioxide from the blood diffuses into the alveoli. Oxygen dissolves in the moist lining Oxygen diffuses into the blood

27. Gas Exchange in the alveoli Oxygen from the air in the alveoli diffuses into the blood. At the same time, carbon dioxide from the blood diffuses into the alveoli. Oxygen dissolves in the moist lining Oxygen diffuses into the blood the blood carries oxygen to the cells

28. Gas Exchange in the alveoli Oxygen from the air in the alveoli diffuses into the blood. At the same time, carbon dioxide from the blood diffuses into the alveoli. Oxygen dissolves in the moist lining Oxygen diffuses into the blood the blood carries oxygen to the cells cells of the body use oxygen for respiration

29. Gas Exchange in the alveoli Oxygen from the air in the alveoli diffuses into the blood. At the same time, carbon dioxide from the blood diffuses into the alveoli. Oxygen dissolves in the moist lining Oxygen diffuses into the blood the blood carries oxygen to the cells cells of the body use oxygen for respiration carbon dioxide goes into the blood

30. Gas Exchange in the alveoli Oxygen from the air in the alveoli diffuses into the blood. At the same time, carbon dioxide from the blood diffuses into the alveoli. Oxygen dissolves in the moist lining Oxygen diffuses into the blood the blood carries oxygen to the cells cells of the body use oxygen for respiration carbon dioxide goes into the blood the blood carries carbon dioxide to the lungs

31. Gas Exchange in the alveoli Oxygen from the air in the alveoli diffuses into the blood. At the same time, carbon dioxide from the blood diffuses into the alveoli. Oxygen dissolves in the moist lining Oxygen diffuses into the blood the blood carries oxygen to the cells cells of the body use oxygen for respiration carbon dioxide goes into the blood the blood carries carbon dioxide to the lungs carbon dioxide diffuses into the alveoli

32. Breathing

33. Breathing Breathing in (inspiration)

34. Breathing Breathing in (inspiration) intercostal muscles contract

35. Breathing Breathing in (inspiration) intercostal muscles contract rib cage moves up and out

36. Breathing Breathing in (inspiration) intercostal muscles contract rib cage moves up and out diaphragm becomes flatter when the muscle contracts

37. Breathing Breathing in (inspiration) intercostal muscles contract rib cage moves up and out diaphragm becomes flatter when the muscle contracts air rushes in

38. Breathing Breathing in (inspiration) intercostal muscles contract rib cage moves up and out diaphragm becomes flatter when the muscle contracts Breathing out (expiration) intercostal muscles relax

39. Breathing Breathing in (inspiration) intercostal muscles contract rib cage moves up and out diaphragm becomes flatter when the muscle contracts Breathing out (expiration) intercostal muscles relax rib cage moves down and in

40. Breathing Breathing in (inspiration) intercostal muscles contract rib cage moves up and out diaphragm becomes flatter when the muscle contracts Breathing out (expiration) intercostal muscles relax rib cage moves down and in diaphragm becomes dome-shaped when the muscle relaxes

41. Breathing Breathing in (inspiration) intercostal muscles contract rib cage moves up and out diaphragm becomes flatter when the muscle contracts intercostal muscles relax rib cage moves down and in diaphragm becomes dome-shaped when the muscle relaxes air is pushed out