![Human lungs
Pharynx
[throat]
Nose
Trachea Larynx
[windpipe]
[voice box]
lung](https://image.slidesharecdn.com/respiratorysystem-130105083655-phpapp01/85/Respiratory-system-12-320.jpg)
![Fig. 1a Structure of human lungs
enclosed by the rib cage.
[plural:
bronchi]
[singular:
alveolus]](https://image.slidesharecdn.com/respiratorysystem-130105083655-phpapp01/85/Respiratory-system-13-320.jpg)
![Examples of lung diseases:
Pneumonia Normal alveoli
[inflammation of alveoli]
Pneumonia](https://image.slidesharecdn.com/respiratorysystem-130105083655-phpapp01/85/Respiratory-system-60-320.jpg)
Respiratory system
- 2. Which gas is: Taken up for respiration? Eliminated as a waste?
- 3. Why does an amoeba NOT require a special respiratory surface but humans do? LARGE surface area to volume ratio
- 5. As animals increase in size their surface area to volume ratio: DECREASES Surface area (cm): Volume (cm3): Surface area/volume:
- 7. Lungs are located in the………… and protected by the:……………
- 8. Thorax is the region above the:……………………….. Name another organ which also is found in the thorax:…………
- 9. What is the advantage of the heart and lungs being located close together? Blood pumped by heart becomes quickly oxygenated.
- 10. Blood supply to & away from lungs
- 12. Human lungs Pharynx [throat] Nose Trachea Larynx [windpipe] [voice box] lung
- 13. Fig. 1a Structure of human lungs enclosed by the rib cage. [plural: bronchi] [singular: alveolus]
- 14. Ribs are held together by:
- 15. Fig. 1b Structure of human lungs.
- 16. The surface area of the lungs is roughly the same size as a tennis court.
- 17. The large surface area of the lungs is provided by……….
- 18. Which structure is located behind the trachea? trachea
- 19. The rings of cartilage keep the trachea open at all times During swallowing. During exhaling.
- 20. Three things happen to the air breathed in as it passes through the nasal passages: Cilia Mucus Cell membrane
- 21. It is better to breathe through the nose rather than the mouth. Why?
- 22. What prevents food from entering the trachea? Epiglottis closes the trachea . trachea
- 23. Sequence air takes to enter the lungs: 2. pharynx 1. nasal passages 4. trachea 3. larynx lung 5. bronchi 6. bronchioles 7. alveoli
- 24. The lungs are placed in an air-tight chamber What happens to the lungs if air enters this chamber? Lung collapses
- 25. Fun Facts At rest, the body takes in and breathes out about 10 liters of air each minute. * The right lung is slightly larger than the left. * The highest recorded "sneeze speed" is 165 km per hour. * The capillaries in the lungs would extend 1,600 kilometers if placed end to end. * We lose half a liter of water a day through breathing. This is the water vapor we see when we breathe onto glass. * A person at rest usually breathes between 12 and 15 times a minute. * The breathing rate is faster in children and women than in men.
- 27. Breathing in / Breathing out/ Inspiration / Expiration / Inhaling Exhaling Diaphragm & intercostal muscles:
- 29. Breathing in:
- 30. Breathing out:
- 33. CHANGES IN THE COMPOSITION OF BREATHED AIR Gas Inhaled % Exhaled % Oxygen 21 16 Carbon dioxide 0.03 4 Nitrogen 79 79 Water vapour variable saturated Why is exhaled air always saturated with water vapour?
- 34. Due to evaporation of film of moisture lining the alveoli
- 35. Gaseous exchange occurs in alveoli pulmonary artery pulmonary vein bronchiole alveolus
- 36. Fig. 5 Gas exchange inside an alveolus.
- 37. Question: SEP, 2008 a) Explain why humans breathe out: i) more carbon dioxide than is breathed in, (2) A waste product that is made all the time by respiration. ii) as much nitrogen as is breathed in. (2) Not used by the body.
- 38. b) Compare the amount of water vapour in inhaled and exhaled air. (2) More present in exhaled air due to evaporation from film of moisture inside alveoli.
- 39. Question: MAY, 2010 Draw a clear well labelled diagram showing how gaseous exchange takes place in the alveolus. (4)
- 40. Fig. 4 A small part of a human lung. Give TWO features of alveoli that aid diffusion of gases. 1. Thin epithelium 2. Dense capillary network 3. Provide a large surface area
- 42. A lighted cigarette produces many harmful chemicals
- 43. Chemicals in cigarette smoke: 1. NICOTINE 2. CARBON MONOXIDE 3. TAR
- 44. 1. NICOTINE increases heart rate and blood pressure person becomes addicted
- 45. 2. CARBON MONOXIDE combines with haemoglobin in red blood cells so reducing the level of oxygen in the blood
- 46. 3. TAR a black sticky material that remains in the lungs
- 47. 3. TAR contains over a thousand chemicals, some of them are carcinogens (substances that cause cancer)
- 48. Some effects of cigarette smoke: 1. Irritate the membrane lining the upper respiratory tract. 2. Cilia stop beating. 3. Extra mucus forms in the trachea and bronchi causing ‘smoker’s cough’.
- 49. Non- smoker Smoker Note more mucus present compared to a non-smoker.
- 50. 4. Smoking weakens the walls of the alveoli and repeated coughing can destroy some of them. This breakdown of alveoli is called emphysema.
- 51. Question: MAY, 2007 Why do people who suffer from emphysema become breathless on minimal physical activity e.g. walking upstairs? (3) Emphysema results in a reduction in lung volume. Less surface area to absorb oxygen. Person cannot produce enough energy.
- 52. Question: MAY, 2010 Explain why: i) patients suffering from emphysema absorb less oxygen; (3) Emphysema is a condition caused by the deterioration of the alveolar wall. This decreases the surface area for absorption therefore there is decreased gaseous exchange (less oxygen uptake). Award half a mark if they mention alveoli burst.
- 53. Question: MAY, 2010 Explain why: ii) emphysema patients tend to hyperventilate (rapid breathing); (3) Emphysema patients try to compensate for the decrease oxygen uptake by taking quick rapid breaths. This increases oxygen concentration in the lungs and therefore increases oxygen absorption.
- 54. Question: MAY, 2010 Explain why: iii) emphysema patients are more prone to pulmonary infections such as bacterial bronchitis. (3) Emphysema is mainly caused by smoking. Cigarette smoke stops the cilia in the breathing system from beating, leading to an accumulation of mucus and microbes in the lungs. Microbes remain in lungs and can infect , bringing about pulmonary infections.
- 55. 5. Babies born to mothers who smoke: are generally lighter than babies born to non-smoking mothers are at a risk of premature birth
- 56. Question: SEP, 2011 Explain why pregnant females are encouraged to avoid smoking. (3) Higher risk for miscarriages. Higher risk for premature birth. Less oxygen reaches embryo – baby is born smaller than average. Chemicals in smoke affect the brain of the embryo and baby is born mentally retarded.
- 57. What is ‘passive smoking’? When people breathe in the smoke from other people’s cigarettes.
- 58. Passive smoking causes risks to health
- 59. Examples of lung diseases: Asthma Lung cancer Bronchitis Emphysema
- 60. Examples of lung diseases: Pneumonia Normal alveoli [inflammation of alveoli] Pneumonia
- 62. Feature Function 1) alveoli present a large to absorb oxygen surface area to allow oxygen to diffuse 2) alveolar lining is very thin into the blood easily 3) alveolar surface is moist to allow oxygen to dissolve 4) a dense capillary network to pick up and transport surrounds the alveoli oxygen 5) a mechanism to renew the to keep a high concentration air in contact with the gradient between the alveoli alveoli and the blood
- 64. Fig. 7 (A) Insect tracheal system.
- 65. Fig. 7 (B) Part of an insect tracheal system.
- 66. Valves & hairs at a spiracle: reduce water loss Valve open Valve closed
- 68. Operculum: is a movable gill cover that encloses and protects the gills
- 69. Operculum
- 70. Fig. 8 (A) Head of herring with operculum cut away to reveal gills.
- 71. Fig. 8 (B) Breathing current in a fish.
- 72. What makes fish gills look red? A rich blood supply.
- 73. Fig. 9 Breathing in a fish.
- 74. The End