Starter What is the name of this cell?

1. Starter What is the name of this cell? What is the main role of this type of cell? This cell is “adapted” so it can carry out its role very efficiently. Describe two such adaptations.

2. Breathing

3. Breathing • The primary function of breathing is to supply the blood with oxygen • Oxygen is needed by every cell in the body to release the energy from glucose in a process called respiration.

4. Asthma

5. Anatomy of Breathing • Oxygen enters the respiratory system through the mouth and the nose. • The oxygen then passes through the larynx (voicebox) and the trachea; which is a tube that enters the chest cavity. • In the chest cavity, the trachea splits into two smaller tubes called the bronchi (singular = bronchus).

6. Anatomy of Breathing • Each bronchus then divides again forming smaller tubes called bronchioles. • The bronchioles lead directly into the lungs where they lead to tiny sacs called alveoli.

9. Alveoli • They are spherical to maxmise the surface area and have very thin walls • The average adult's lungs contain about 600 million of these spongy, air-filled sacs

10. Alveoli • The inhaled oxygen passes into the alveoli through and then diffuses through the capillaries into the blood. • Carbon dioxide from the veins is released into the alveoli and follows the same path out of the lungs when you exhale.

13. Gas exchange at the alveoli The alveoli are bunches of tiny air sacks inside the lungs. Each individual sack is called an alveolus. When you breathe in, they fill with air. The alveoli are covered in tiny capillaries (blood vessels). Gases can pass through the thin walls of each alveolus and capillary, and into the blood stream. Gases can also pass from the blood stream,into the alveolus.

14. Gas exchange at the alveoli

15. The Breathing System

16. The nasal passages and lungs Air is drawn into the body via the nose or mouth. There are advantages to breathing through your nose: • the air is warmed so that it is closer to body temperature • tiny hairs and mucus in the nose filter the air, preventing larger dust and pollen particles reaching the alveoli • mucus moistens the air, making it easier for the alveoli to absorb. Air then travels through the larynx, trachea (windpipe), bronchi (one bronchus to each lung) and bronchioles to the alveoli, where oxygen passes into the bloodstream.

17. Mechanisms of breathing – inspiration When you breathe in: Intercostal muscles pull ribs up and out • intercostal muscles between the ribs contract, pulling the chest walls up and out • the diaphragm muscle below the lungs contracts and flattens, increasing the size of the chest • the lungs increase in size, so the pressure inside them falls. This causes air to rush in through the nose or mouth. Diaphragm contracts and moves down

18. Mechanisms of breathing – expiration When you breathe out: Ribs move in and down • Intercostal muscles between the ribs relax so that the chest walls move in and down. • The diaphragm muscle below the lungs relaxes and bulges up, reducing the size of the chest. • The lungs decrease in size, so the pressure inside increases and air is pushed up the trachea and out through the nose or mouth. Diaphragm relaxes and bulges up

19. Mechanisms of breathing – inspiration

20. Mechanisms of breathing – expiration

21. Aveoli are spherical (ball-shaped), have thin and moist walls, and surrounded by many capillaries. Explain why: Aveoli are spherical Aveoli have thin and moist walls Aveoli are surrounded by many capillaries

23. Gas exchange at the alveoli

24. MRS GREN? What is “respiration”?

25. What is respiration? useful! waste product exhaled waste product exhaled from the digestive system from the breathing system Respirationis the process that the body uses to release energy from digested food (glucose): energy glucose water oxygen carbon dioxide This type of respiration is called aerobicrespiration because energy is released with oxygen. How do the glucose and oxygen needed for aerobic respiration get to the all the body’s cells?

26. Aerobic and anaerobic respiration Aerobic respiration When the body is able to supply the cells with the oxygen and glucose that they need, it carries out aerobic respiration. energy glucose water oxygen carbon dioxide Anaerobic respiration When the body cannot supply the cells with the oxygen needed to break down glucose, then it has to carry out anaerobic respiration. Energy is released without oxygen: energy glucose lactic acid

27. Not enough oxygen! energy glucose lactic acid lactic acid water oxygen carbon dioxide When anaerobic respiration takes place, the lactic acid produced soaks the muscle cells and prevents muscles from doing their job. This causes fatigue and sometimes cramp. After activity that has lead to anaerobic respiration, the person involved pants and breathes heavily. This happens because they need lots of oxygen to get rid of lactic acid that has built up in their body.

29. What is respiration? useful! waste product exhaled waste product exhaled from the digestive system from the breathing system Respirationis the process that the body uses to release energy from digested food (glucose) by reacting it with oxygen. energy glucose water oxygen carbon dioxide

30. What is respiration? Describe in words. Write down the respiration equation. Why do we breathe? How is breathing different from respiration? What is gas exchange?

31. Gas exchange at the alveoli

32. Inhaled air vs. Exhaled air 21% Very small amount 79% Small amount 17% 3% 79% Large amount Find the differences Explain the differences

33. Questions 1. Why are there less oxygen and more carbon dioxide in the exhaled air? 2. Why is the amount of nitrogen unchanged?

34. Comparing inhaled and exhaled air inhaled air exhaled air nitrogen (78%) oxygen (21%) carbon dioxide (0.04%) other nitrogen (78%) oxygen (17%) carbon dioxide (4%) other What are the differences between inhaled and exhaled air? How could you test for the differences between inhaled and exhaled air?

35. Practical – Air goes in, Air goes out

36. Practical – How much air can you breathe in?

37. Questions: • What is the benefit of the lungs having tiny air sacs rather than just one large structure? • What process enables oxygen and carbon dioxide to move across the alveolus wall? • How is the alveolus wall adapted for efficient movement of gas molecules? • What is the name of the red pigment in blood that bonds with oxygen?

38. The respiratory system and health Why is a respiratory system that works properly essential for good health? The respiratory system provides the body with the oxygen it needs for respiration. The lungs are delicate, spongy organs that deal with 12,000 litres of air each day. Smoking is a very dangerous habit that has serious effects on the lungs and respiratory system. How does smoking damage health and fitness?

39. What is respiration? Describe in words. Write down the respiration equation. Why do we breathe? How is breathing different from respiration? What is gas exchange?

40. Write down the respiration equation (in words) What are the three differences between inhaled air and exhaled air? What would happen to the body if alveoli inside the lungs are filled with liquid?

41. Asthma

42. Bronchitis

43. Emphysema Caused by exposure to toxic chemicals or long-term exposure to tobacco smoke.

44. Emphysema

45. How does smoking affect the lungs? Which picture shows the healthy lungs of a non-smoker and which show the unhealthy lungs of a smoker? healthy lungs smoker’s lungs Not a difficult question to answer but some people still think that smoking is cool!

46. How does smoking affect health? dental hygiene problems lung cancer asthma heart disease impaired immune system facial wrinkles cervical cancer emphysema kidney cancer Effects of smoking on health mouth, lip and throat cancer leukaemia bronchitis sperm abnormalities and impotence pancreatic cancer testicular cancer osteoporosis stomach cancer menstrual problems liver cancer bladder cancer

47. Smoker’s cough