Respiration<br />The Breath of Life<br />
Lesson OutLine<br />RESPIRATION<br />Aerobic Vs Anaerobic Respiration<br />Anatomy of the Respiratory System<br />Smoking ...
Learning Objectives<br />By the end of the lesson, you should be able to:<br />Define aerobic respiration as the release o...
Energy Makes the World Goes Round<br />Everything in the world works only because they could use energy.<br />and Life is ...
Burning Food… …<br />Early Earth is a tough neighbourhood<br />Earth was borne out of the solar nebula without oxygen.<br ...
A Thirst for Energy -An Ancient Battle<br />Life didn’t really need oxygen, but there is one thing that all life needs… an...
ENERGY <br />
How does body convert energy stored in food                                energy for body use?<br />
Respiration<br />PG 194<br />Definition: <br /><ul><li>Respiration is the oxidation of food substances (glucose)with the r...
Respiration is a characteristic of life since all living things require energy for essential activities</li></ul>2 Types o...
Aerobic and Anaerobic Respiration<br />	C6H12O6		2C3H6O3	+	energy<br />	glucose		lactic		<br />			acid<br /><ul><li>Occur...
Leads to fatigue.</li></ul>RESPIRATION<br />	C6H12O6+	6O2		6CO2	+	6H2O	+	energy<br />	glucose		oxygen		carbon		water<br /...
Aerobic and Anaerobic Respiration<br /><ul><li>Those who uses oxygen to oxidize food:
Those who do not use oxygen to oxidize food:</li></ul>Aerobic Respiration<br /><ul><li>is the oxidation of glucose in the ...
Carbon dioxide and water are released as waste products.</li></ul>Anaerobic Respiration<br />is the breakdown of food mole...
Aerobic Respiration<br />Glucose + oxygen                                                                                 ...
Aerobic respiration generate heat, which is circulated around the body to maintain a constant optimum body temperature
Many processes in living organisms require energy:
Active transport
Muscular contractions
Catabolism (Breaking up of complex molecules)
Anabolism (Building up of complex molecules)
 Cell division
Transmission of nerve impulses</li></li></ul><li>Anaerobic respiration<br />Pg 195-196<br />Definition:<br />Anaerobic res...
The ethanol/lactic acid produced still contain much energy.
Hence only a small amount of energy is released in the process</li></ul>Glucose  Carbon dioxide + ethanol + little energy...
Some microbes living in the mud… low oxygen level …<br />Respire ananerobically!<br />
Yeast!<br />Glucose  (with yeast)<br />Carbon dioxide +ethanol+ little energy<br />
Alcoholic Fermentation<br />Anaerobic respiration<br />Glucose  (with yeast)<br />Carbon dioxide + ethanol+ little  energ...
Anaerobic Respiration<br />Glucose  (with baker’s yeast)<br />Carbon dioxide +ethanol+ little  energy<br />
Anaerobic respiration in humans!<br />Highly intensive exercise<br />Glucose    Lactic acid + energy<br />
Production of lactic acid<br />PG 196<br />In Muscles<br />During strenuous exercise, the breathing rate and heartbeat wil...
What happens when you need more energy but not enough oxygen?<br />PG 196<br />
Anaerobic Respiration in the Muscles<br />Vigorous muscle movement increase rate of aerobic respiration (oxidation of gluc...
PG 196-197<br />During recovery…<br />Breathing rate continues to be fast.<br />Provides oxygen to repay oxygen debt.<br /...
Oxygen debt<br />PG 196-197<br />The amount of oxygen needed to dispose of the lactic acid is called oxygen debt<br />The ...
PG 196<br />Energy needed for vigorous exercise<br />Aerobic respiration <br />Glucose + oxygen  Carbon dioxide + water +...
Investigation 10.3 (page 199)<br />3	To allow oxygen to diffuse in and carbon dioxide to diffuse out of the flask.<br />5	...
Test Yourself (Page 200)<br />Test Yourself! (page 200)<br />1(a)	The solution would turn yellow. The snail would respire ...
2(a)    	The set-up would be similar to that in question 3, if the boiling tube in  <br />	question 3 were replaced by the...
How do organisms obtain oxygen for aerobic respiration?<br /><ul><li>Gaseous exchange:                                   E...
Learning Objectives<br />By the end of the lesson, you should be able to:<br />identify on diagrams and name the larynx, t...
Adaptations to Land Living<br /><ul><li>Oxygen must be dissolved before it can be absorbed.
As such all respiratory surfaces must be moist.
This is no problem for an aquatic animal such as a fish.
What about terrestrial animals?</li></li></ul><li>Respiratory surfaces<br />The surface through which respiratory gases ar...
Adaptations to Land Living<br /><ul><li>As the first vertebrate animal venture onto land, obtaining oxygen becomes a garga...
There is little moisture for the respiratory surface to function properly.</li></li></ul><li>Respiratory Surfaces<br /><ul...
Allow animal to dissolve oxygen from the air directly into the moist respiratory surfaces.</li></li></ul><li>Characteristi...
Anatomy of the Human Respiratory System<br />
Anatomy of the Human Respiratory System<br />
6 August 2011<br />Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd. <br />Path of Air Through ...
6 August 2011<br />Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd. <br />Path of Air Through ...
6 August 2011<br />Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd. <br />Path of Air Through ...
Nasal Passages (Nasal cavity)<br />Lined with moist mucus membrane.<br />Advantages of breathing through nose:<br />Hairsa...
Path of Air Through the Respiratory System<br />atmosphere <br />external nostril <br />nasal passages<br />Pharynx (throa...
6 August 2011<br />Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd. <br />Path of Air Through ...
 Has cartilage to keep it open
Is the voicebox with vocal chords stretched across it</li></li></ul><li>6 August 2011<br />Path of Air Through the Respira...
 Inner wall lined with cilia and mucous membrane
 Cilia beat rhythmically and move particles away from lungs</li></li></ul><li>Trachea or Windpipe<br />
Trachea<br />Contains C-shaped cartilage<br />Keeps airways opened and prevent it from collapsing<br />
6 August 2011<br />Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd. <br />Path of Air Through ...
Adaptations of the Trachea & Bronchi WALL<br /><ul><li>Gland cells secrete mucus</li></ul>to trap dust particles and bact...
Adaptations of the Trachea & Bronchi<br />
6 August 2011<br />Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd. <br />Path of Air Through ...
Path of Air Through the Respiratory System<br />atmosphere <br />external nostril <br />nasal passages<br />pharynx<br />l...
Structure of Alveolus (Plural:alveoli)<br />
Passage of air through respiratory system<br />
One-cell thick wall<br />Oxygen <br />
Adaptations of the alveoli for efficient gaseous exchange<br />
How does the breathing mechanism works?<br />
PG 205<br />What causes air movement into the lungs?<br />Vertebral  column<br />sternum<br />ribcage<br />lung<br />Inter...
  The workings of the intercoastal muscles and the diaphragm changes the volume of the thoracic cavity<br />PG 205<br />Me...
PG 206 <br />Mechanism of Breathing - Inhalation<br />When you breathe in or inhale, the following events take place:<br /...
PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> Your diaphragm contracts and flattens.</li></ul>Movement of ...
PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> Your external intercostal muscles contract while your intern...
PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> Your ribs move upwards and outwards. Your sternum also moves...
PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> The volume of your thoracic cavity increases.</li></ul>Movem...
PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> Air pressure in your lungs causes them to expand to fill up ...
PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> Expansion of your lungs causes the air pressure inside them ...
PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> Atmospheric pressure is now higher than the pressure within ...
PG 206<br />Mechanism of Breathing - Inhalation<br />What causes air movement into the lungs?<br />Diaphragm contracts<br ...
PG 206<br />Mechanism of Breathing - Inhalation<br />Demonstration of Changes in Physical Parameters<br />Volume in thorac...
PG 207<br />Mechanism of Breathing -Exhalation<br />When you breathe out or exhale, the following events take place:<br />...
PG 207<br />Mechanism of Breathing - Exhalation<br /><ul><li> Your diaphragm relaxes and arches upwards.</li></ul>Movement...
PG 207<br />Mechanism of Breathing- Exhalation<br /><ul><li> Your internal intercostal muscles contract while your externa...
PG 207<br />Mechanism of Breathing - Exhalation<br /><ul><li> Your ribs move downwards and inwards. Your sternum also move...
PG 207<br />Mechanism of Breathing - Exhalation<br /><ul><li> The volume of your thoracic cavity decreases.</li></ul>Movem...
6 August 2011<br />PG 207<br />Mechanism of Breathing - Exhalation<br /><ul><li> Your lungs are compressed and air pressur...
6 August 2011<br />PG 207<br />Mechanism of Breathing - Exhalation<br /><ul><li> Air pressure within the lungs is  now hig...
6 August 2011<br />Mechanism of Breathing<br />What happens to your intercostal muscles when you are breathing?<br />
PG 207<br />Mechanism of Breathing<br />What happens to your intercostal muscles when you are breathing?<br />R<br />When ...
PG 207<br />Mechanism of Breathing<br />What happens to your intercostal muscles when you are breathing?<br />R<br />When ...
Mechanism of Breathing - Exhalation<br />Demonstration of Changes in Physical Parameters<br />Volume in thoracic cavity de...
PG 207<br />Summary of Breathing Mechanism<br />
Learning Objectives<br />By the end of the lesson, you should be able to:<br />State the characteristics and role of alveo...
Breathing and Gaseous Exchange<br />Breathing<br />Gaseous Exchange<br />Between alveolus & blood capillary<br />Oxygen<br...
Mechanics of Breathing - Expiration<br />What causes air movement out of the lungs?<br />Diaphragm ________________ .<br /...
Pg 208<br />Breathing and Gaseous Exchange<br />Breathing<br />Gaseous Exchange<br />Between alveolus & blood capillary<br...
Gaseous exchange at alveolus<br />Pg 208<br />
Gaseous exchange<br />Pg 208<br />Alveolus<br />Cells<br />Capillaries<br />
Pg 208<br />Gaseous Exchange- Oxygen<br />How is oxygen taken into the blood capillaries during inspiration?<br />PART 1 –...
Gaseous Exchange- Oxygen<br />Pg 208<br />How is oxygen taken into the blood capillaries during inspiration?<br />PART 2 –...
Gaseous Exchange- Oxygen Transport in body<br />Pg 208<br />How is oxygen taken into the blood capillaries during inspirat...
Pg 209<br />Gaseous Exchange- Carbon Dioxide Transport in body <br />In Actively Respiring Tissues & Blood plasma<br />CO2...
Gaseous Exchange- Carbon Dioxide<br />In Lung Tissues<br />Hydrogen carbonate anions in blood recombines with H+ to form c...
Gaseous Exchange- Carbon Dioxide<br />
Oxygen and carbon dioxide concentration gradient between alveolar air and blood are maintained by:-A continuous flow of bl...
Pg 211<br />Comparing Inspired & Expired Air<br />Why is it important to compare inspired and expired air?<br /><ul><li>Be...
See experiments on page 210-211</li></li></ul><li>Pg 212<br />Stimulus for Breathing<br />What causes the breathing?<br />...
Test Yourself (Page 213)<br />INCREASE Rate of diffusion of oxygen from the lungs into the blood and of carbon dioxide out...
Learning Objectives<br />By the end of the lesson, you should be able to:<br />identify on diagrams and name the larynx, t...
Learning Objectives<br />By the end of the lesson, you should be able to:<br />describe the effects of constituents of tob...
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Respiration

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  • - Different organisms have several alternative ways of getting energy from food, without using oxygen, but all are less efficient than aerobic respiration, and do not break food down fully into the simplest substances.Some organisms they live in places where there is very little oxygen such as these muddy soils. So how do they get energy? To survive in this habitat, the microbes have to adapt by using anaerobic respiration to provide them with energy. Although anaerobic respiration is a primitive and inefficient form of energy release, deriving from the period when oxygen was missing from the atmosphere, it can also be seen as an adaptation. To survive in some habitats, such as the muddy bottom of a polluted river, an organism must be to a large extent independent of oxygen; such habitats are said to be anoxic. In the thick mud at the bottom of this pond, there is very little oxygen. Some bacteris live in this mud. They break down glucose without using osygen. So they respire anaerobically. During anaerobic respiration, less energy is released than aerobic, because the glucose molecule is only partly broken down. Co2 is released, alcohol may be formed as a waste product. And we call this fermentation to make alcoholic drinks.
  • What is this? This is used to make your wine and bread. Yeast are a type of fungi. Yeasts are characterized by a wide dispersion of natural habitats. Common on plant leaves and flowers, soil and salt water. Yeasts are also found on the skin surfaces and in the intestinal tracts of warm-blooded animals, where they may live symbiotically or as parasites.Use of anaerobic respiration in industryIn plants, yeasts, and bacteria, anaerobic respiration results in the production of alcohol and carbon dioxide, a process that is exploited by both the brewing and the baking industries (see fermentation).Many industries have made use of the waste pdts from yeast’s ananerobicresoiration(c02 and ethanol) to make useful pdts. Can you make a guess to what they are?
  • If u look closely at many fruits e.g grapes, there are yeast living on their surface. And we know yeast respire anerobically and grapes is made up of sugar. So if you were to store these fruits with yeast on it for a while, u will taste alcohol. Becos the yeast can undergo anaerobic respiration and breakdown the sugar to give alcohol. Another term for anaerobic respiration is fermentation, or alcoholic fermentation, since it produces alcohol. So what brewery industry does is they add yeast to food such as rice, barley, corn whereby yeast will ferment the sugar in these food to produce alcoholic beverages such as wine and beer.
  • in the baking industry the bakers also use yeast to make bread. And the yeast used is called baker’s yeast. Bakers are more interested in the carbon dioxide released rather than the alcohol.Yeast is added to dough, the yeast starts to feed on he sugar in the flour, fermenting the sugar to give co2, which expand and cause dough to be raised. So when its put in the oven, the heat will kill the yeast and evaporate the alcohol, leaving behind light bread with light, fluffy texture. Some of the bread u eat is made with yeast.
  • Besides some bacteria and yeast which respire anaerobically, larger organisms like humans too! Who ran for last sat’s sports day? How did you feel when you were running during the race? Were u breathing very hard? After the race, were you panting?During an intensive exercise such as sprinting, initially, your body undergo aerobic respiration to provide energy to power the run. But if you are exercising so intensely, you may reach a point where you cannot take in oxygen any faster. You are making energy by aerobic respiration as fast as you can, but your body still needs more energy. So where does your body get more energy from to sustain your run? At this point, some of the glucose will be broken down anaerobically, due to insufficient oxygen, to provide a bit of extra energy.And in this case, for human, the waste product is not alcohol; bit lactic acid. So after your run, u will usually see the runners, breathing heavily and catching their breath even though they have stopped running. That’s because, during the run, lactic acid has build up in the leg muscle, so the runners need to breath fast and gard to get extra energy to break down the accumulated lactic acid to pay back the oxygen debt built up during the sprint.
  • Transcript of "Respiration "

    1. 1. Respiration<br />The Breath of Life<br />
    2. 2. Lesson OutLine<br />RESPIRATION<br />Aerobic Vs Anaerobic Respiration<br />Anatomy of the Respiratory System<br />Smoking and Lung Diseases<br />Physiology of the Respiratory System<br />Mechanism of Breathing<br />Aerobic Respiration<br />Anaerobic Respiration<br />
    3. 3. Learning Objectives<br />By the end of the lesson, you should be able to:<br />Define aerobic respiration as the release of a relatively large amount of energy by the breakdown of food substances in the presence of oxygen<br />State the equation (in words and symbols) for aerobic respiration<br />Define anaerobic respiration as the release of a relatively small amount of energy by the breakdown of food substances in the absence of oxygen<br />State the equation (in words only) for anaerobic respiration in humans<br />
    4. 4. Energy Makes the World Goes Round<br />Everything in the world works only because they could use energy.<br />and Life is no exception…<br />
    5. 5. Burning Food… …<br />Early Earth is a tough neighbourhood<br />Earth was borne out of the solar nebula without oxygen.<br />Why is this so?<br />If there was no oxygen, how did life begin?<br />
    6. 6. A Thirst for Energy -An Ancient Battle<br />Life didn’t really need oxygen, but there is one thing that all life needs… and that is Energy.<br />The battle for energy is an ancient one, and even today, people war with one another for sources of energy such as fossil fuel.<br />Sulphur Bacteria<br />Methanogens<br />
    7. 7.
    8. 8. ENERGY <br />
    9. 9. How does body convert energy stored in food  energy for body use?<br />
    10. 10. Respiration<br />PG 194<br />Definition: <br /><ul><li>Respiration is the oxidation of food substances (glucose)with the release of energy in living cells
    11. 11. Respiration is a characteristic of life since all living things require energy for essential activities</li></ul>2 Types of : Aerobic and Anaerobic respiration<br />
    12. 12. Aerobic and Anaerobic Respiration<br /> C6H12O6  2C3H6O3 + energy<br /> glucose lactic <br /> acid<br /><ul><li>Occurs in muscle cells.
    13. 13. Leads to fatigue.</li></ul>RESPIRATION<br /> C6H12O6+ 6O2  6CO2 + 6H2O + energy<br /> glucose oxygen carbon water<br /> dioxide<br /> C6H12O6  2C2H5OH + 2CO2 + energy<br /> glucose ethanol carbon<br /> dioxide<br /><ul><li>Occurs in yeast cells.</li></ul>Aerobic Respiration<br />Anaerobic Respiration<br />Alcoholic Fermentation<br />Lactic Acid Production<br />Aerobic Respiration<br />Alcoholic Fermentation<br />Lactic Acid Production<br />
    14. 14. Aerobic and Anaerobic Respiration<br /><ul><li>Those who uses oxygen to oxidize food:
    15. 15. Those who do not use oxygen to oxidize food:</li></ul>Aerobic Respiration<br /><ul><li>is the oxidation of glucose in the presence of oxygen with the release of a large amount of energy.
    16. 16. Carbon dioxide and water are released as waste products.</li></ul>Anaerobic Respiration<br />is the breakdown of food molecules in the absence of oxygen. Anaerobic respiration releases less energy than aerobic respiration.<br />
    17. 17. Aerobic Respiration<br />Glucose + oxygen  carbon dioxide + water + release large amount of energy <br /><ul><li>Catalysed by enzymes
    18. 18. Aerobic respiration generate heat, which is circulated around the body to maintain a constant optimum body temperature
    19. 19. Many processes in living organisms require energy:
    20. 20. Active transport
    21. 21. Muscular contractions
    22. 22. Catabolism (Breaking up of complex molecules)
    23. 23. Anabolism (Building up of complex molecules)
    24. 24. Cell division
    25. 25. Transmission of nerve impulses</li></li></ul><li>Anaerobic respiration<br />Pg 195-196<br />Definition:<br />Anaerobic respiration is the release of a relatively small amount of energy by the breakdown of food substances in absence of oxygen<br /><ul><li>Glucose is only partially broken down.
    26. 26. The ethanol/lactic acid produced still contain much energy.
    27. 27. Hence only a small amount of energy is released in the process</li></ul>Glucose  Carbon dioxide + ethanol + little energy<br />Glucose  Lactic acid + little energy<br />
    28. 28. Some microbes living in the mud… low oxygen level …<br />Respire ananerobically!<br />
    29. 29. Yeast!<br />Glucose (with yeast)<br />Carbon dioxide +ethanol+ little energy<br />
    30. 30. Alcoholic Fermentation<br />Anaerobic respiration<br />Glucose (with yeast)<br />Carbon dioxide + ethanol+ little energy<br />
    31. 31. Anaerobic Respiration<br />Glucose (with baker’s yeast)<br />Carbon dioxide +ethanol+ little energy<br />
    32. 32. Anaerobic respiration in humans!<br />Highly intensive exercise<br />Glucose  Lactic acid + energy<br />
    33. 33. Production of lactic acid<br />PG 196<br />In Muscles<br />During strenuous exercise, the breathing rate and heartbeat will be increased so that oxygen can be brought faster to muscles<br />There is a limit to rate of breathing and heartbeat<br />Extra energy for strenuous exercise is thus produced by anaerobic respiration in muscles<br />
    34. 34. What happens when you need more energy but not enough oxygen?<br />PG 196<br />
    35. 35. Anaerobic Respiration in the Muscles<br />Vigorous muscle movement increase rate of aerobic respiration (oxidation of glucose) to release more energy.<br />Prolonged muscular contraction<br />2. Insufficient oxygen available leads to muscle cells undergoing anaerobic respirationto release even more energy.<br />3. Lactic acid accumulates in muscles causing fatigue, muscle pain, cramps.<br />4. Muscle cells incur oxygen debt.<br />PG 196<br />
    36. 36. PG 196-197<br />During recovery…<br />Breathing rate continues to be fast.<br />Provides oxygen to repay oxygen debt.<br />Oxygen can break down lactic acid:<br />to produce energy<br />Convert lactic acid back into glucose<br />Oxygen debt is repaid when lactic acid is used up.<br />“Repaying” oxygen debt<br />
    37. 37. Oxygen debt<br />PG 196-197<br />The amount of oxygen needed to dispose of the lactic acid is called oxygen debt<br />The time taken to remove all the lactic acid is called the recovery period<br />
    38. 38. PG 196<br />Energy needed for vigorous exercise<br />Aerobic respiration <br />Glucose + oxygen  Carbon dioxide + water + energy<br />Anaerobic respiration <br /> Glucose + Oxygen  Lactic acid + little energy<br />Total amount of energy needed for vigorous muscular contractions<br />
    39. 39. Investigation 10.3 (page 199)<br />3 To allow oxygen to diffuse in and carbon dioxide to diffuse out of the flask.<br />5 The reading should be higher than room temperature for flask A. Germinating seeds release heat during respiration.<br />6 Advantages are:<br /> a) fewer seeds need to be used.<br /> b) the thermometers need not be inserted too deeply into the flask so that they can be read more easily.<br />
    40. 40. Test Yourself (Page 200)<br />Test Yourself! (page 200)<br />1(a) The solution would turn yellow. The snail would respire and give out carbon dioxide. Carbon dioxide would dissolve in the water to form carbonic acid.<br />(b) The solution would turn purple. The green plant would photo synthesise and remove carbon dioxide from the solution.<br />(c) Any carbon dioxide released by the snail is used up by the plant for photosynthesis. The rate of photosynthesis = the rate of respiration in both organisms.<br />No. It serves as a control.<br />23(a) Rate of oxygen uptake<br /> (b) To absorb carbon dioxide<br /> (c) To the left<br /> (d) Rate of oxygen uptake = (100 X (  X 12)/2) mm2/minute<br />4 Refer to Investigation 10.2 (page 199).<br />
    41. 41. 2(a) The set-up would be similar to that in question 3, if the boiling tube in <br /> question 3 were replaced by the conical flask containing germinating bean seeds. The tube of sodium hydroxide could be suspended within the flask.<br />(b) The sodium hydroxide would absorb any carbon dioxide produced as a result of respiration, therefore any change in the volume of air inside the flask would be due to the uptake of oxygen by the seeds. As oxygen is taken up by the seeds, the droplet of coloured water would move along the capillary tube. The position of the coloured droplet would indicate the volume of oxygen taken in. Readings would be taken at suitable time intervals, e.g. 5 s, 10 s, 15 s and then averaged to find out the rate of oxygen uptake by the germinating seeds.<br />(c) Changes in the temperature of the surroundings may affect the rate of oxygen uptake by the germinating bean seeds. The temperature of the surroundings should be kept constant (set-up should be placed in a warm environment as the seeds are germinating). <br />
    42. 42. How do organisms obtain oxygen for aerobic respiration?<br /><ul><li>Gaseous exchange: Exchange of gases between an organism and the environment</li></ul>How do human carry out gaseous exchange?<br />
    43. 43. Learning Objectives<br />By the end of the lesson, you should be able to:<br />identify on diagrams and name the larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries<br />state the characteristics of, and describe the role of, the exchange surface of the alveoli in gaseous exchange<br />describe the role of cilia, diaphragm, ribs and intercostal muscles in breathing<br />
    44. 44. Adaptations to Land Living<br /><ul><li>Oxygen must be dissolved before it can be absorbed.
    45. 45. As such all respiratory surfaces must be moist.
    46. 46. This is no problem for an aquatic animal such as a fish.
    47. 47. What about terrestrial animals?</li></li></ul><li>Respiratory surfaces<br />The surface through which respiratory gases are exchanged between the organism’s internal and external environment<br />The actual design of the surface depends on factors like habitat, size and activity of organism<br />E.g. Lungs –mammals, birds, reptiles, amphibians<br /> Gills –Fish, amphibians<br />Tracheoles – Arthropods<br /> Leaf cells – Plants<br /> Body covering- small animals (amoeba, earthworm)<br />
    48. 48. Adaptations to Land Living<br /><ul><li>As the first vertebrate animal venture onto land, obtaining oxygen becomes a gargantuan task.
    49. 49. There is little moisture for the respiratory surface to function properly.</li></li></ul><li>Respiratory Surfaces<br /><ul><li>Moist respiratory surface (air sacs are located in body cavity)
    50. 50. Allow animal to dissolve oxygen from the air directly into the moist respiratory surfaces.</li></li></ul><li>Characteristics of Respiratory Surfaces<br />Moist surface for oxygen to dissolve<br />Large surface area to volume ratio for gasesous exchange<br />Thin-walled ensure a faster rate of diffusion/exchange of gases<br />Close association with circulatory system: <br />Richly supplied with blood capillaries (continuous blood flow maintains steep diffusion gradient) <br /> Rate of diffusion of gases across respiratory surfaces is increased <br />
    51. 51. Anatomy of the Human Respiratory System<br />
    52. 52. Anatomy of the Human Respiratory System<br />
    53. 53. 6 August 2011<br />Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd. <br />Path of Air Through the Respiratory System<br />atmosphere <br />
    54. 54. 6 August 2011<br />Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd. <br />Path of Air Through the Respiratory System<br />atmosphere <br />external nostril<br />external nostril<br />
    55. 55. 6 August 2011<br />Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd. <br />Path of Air Through the Respiratory System<br />atmosphere <br />external nostril <br />nasal passages (lined with moist mucus membrane)<br />nasal passages<br />external nostril<br />
    56. 56. Nasal Passages (Nasal cavity)<br />Lined with moist mucus membrane.<br />Advantages of breathing through nose:<br />Hairsand moist mucous membrane lining alls of external nostrils filter air, trap dust and foreign particles<br />Blood capillaries and mucuswarm and moisten air respectively before entry into lungs.<br />Sensory cells(small receptor cells) in mucous membrane may detect harmful chemicals in the air (sense of smell)<br />
    57. 57. Path of Air Through the Respiratory System<br />atmosphere <br />external nostril <br />nasal passages<br />Pharynx (throat)<br />nasal passages<br />pharynx<br />external nostril<br /> Located behind the mouth cavity, air passes through it on the way to glottis<br />
    58. 58. 6 August 2011<br />Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd. <br />Path of Air Through the Respiratory System<br />atmosphere <br />external nostril <br />nasal passages<br />pharynx<br />Larynx (Adam’s Apple)<br />nasal passages<br />pharynx<br />external nostril<br />larynx<br /><ul><li>Situated at top of trachea
    59. 59. Has cartilage to keep it open
    60. 60. Is the voicebox with vocal chords stretched across it</li></li></ul><li>6 August 2011<br />Path of Air Through the Respiratory System<br />atmosphere <br />external nostril <br />nasal passages<br />pharynx<br />larynx<br />Trachea (Windpipe)<br />nasal passages<br />pharynx<br />external nostril<br />larynx<br />trachea<br /><ul><li>A long tube supported by C-shaped rings of cartilage to keep it open.
    61. 61. Inner wall lined with cilia and mucous membrane
    62. 62. Cilia beat rhythmically and move particles away from lungs</li></li></ul><li>Trachea or Windpipe<br />
    63. 63. Trachea<br />Contains C-shaped cartilage<br />Keeps airways opened and prevent it from collapsing<br />
    64. 64. 6 August 2011<br />Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd. <br />Path of Air Through the Respiratory System<br />atmosphere <br />external nostril <br />nasal passages<br />pharynx<br />larynx<br />trachea<br />bronchi<br />nasal passages<br />pharynx<br />external nostril<br />larynx<br />trachea<br />bronchi<br />
    65. 65. Adaptations of the Trachea & Bronchi WALL<br /><ul><li>Gland cells secrete mucus</li></ul>to trap dust particles and bacteria<br /><ul><li>Lined with epithelium bearing cilia</li></ul> Cilia: sweeps particles upwards to pharynx<br />
    66. 66. Adaptations of the Trachea & Bronchi<br />
    67. 67. 6 August 2011<br />Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd. <br />Path of Air Through the Respiratory System<br />atmosphere <br />external nostril <br />nasal passages<br />pharynx<br />larynx<br />trachea<br />bronchi<br />Bronchioles (Not supported by cartilage)<br />nasal passages<br />pharynx<br />external nostril<br />larynx<br />trachea<br />bronchi<br />bronchioles<br />
    68. 68. Path of Air Through the Respiratory System<br />atmosphere <br />external nostril <br />nasal passages<br />pharynx<br />larynx<br />trachea<br />bronchi<br />bronchioles<br />Alveoli (For gaseous exchange)<br />nasal passages<br />pharynx<br />external nostril<br />larynx<br />trachea<br />bronchi<br />cluster of alveoli (air sacs)<br />bronchioles<br />
    69. 69. Structure of Alveolus (Plural:alveoli)<br />
    70. 70. Passage of air through respiratory system<br />
    71. 71.
    72. 72. One-cell thick wall<br />Oxygen <br />
    73. 73. Adaptations of the alveoli for efficient gaseous exchange<br />
    74. 74. How does the breathing mechanism works?<br />
    75. 75. PG 205<br />What causes air movement into the lungs?<br />Vertebral column<br />sternum<br />ribcage<br />lung<br />Internal intercostal muscle<br />External intercostal muscle<br />Diaphragm <br />
    76. 76. The workings of the intercoastal muscles and the diaphragm changes the volume of the thoracic cavity<br />PG 205<br />Mechanism of Breathing<br />
    77. 77. PG 206 <br />Mechanism of Breathing - Inhalation<br />When you breathe in or inhale, the following events take place:<br />Movement of rib cage during inhalation<br />Front view<br />Side view<br />TB PG <br />vertebral column<br />sternum<br />rib<br />rib cage<br />
    78. 78. PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> Your diaphragm contracts and flattens.</li></ul>Movement of rib cage during exhalation<br />Front view<br />Side view<br />vertebral column<br />sternum<br />rib<br />rib cage<br />diaphragm contracts and flattens<br />
    79. 79. PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> Your external intercostal muscles contract while your internal intercostal muscles relax.</li></ul>Movement of rib cage during inspiration<br />Front view<br />Side view<br />vertebral column<br />sternum<br />rib<br />rib cage<br />diaphragm contracts and flattens<br />
    80. 80. PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> Your ribs move upwards and outwards. Your sternum also moves up and forward. </li></ul>Movement of rib cage during inspiration<br />Front view<br />Side view<br />vertebral column<br />ribs and sternum raised<br />sternum<br />rib<br />ribs and sternum raised<br />rib cage<br />diaphragm contracts and flattens<br />Ribs swing up<br />
    81. 81. PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> The volume of your thoracic cavity increases.</li></ul>Movement of rib cage during inspiration<br />Front view<br />Side view<br />volume of thorax increases<br />vertebral column<br />ribs and sternum raised<br />sternum<br />rib<br />ribs and sternum raised<br />rib cage<br />diaphragm contracts and flattens<br />Ribs swing up and increase volume of thorax<br />
    82. 82. PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> Air pressure in your lungs causes them to expand to fill up the enlarged space in your thorax.</li></ul>Movement of rib cage during inspiration<br />Front view<br />Side view<br />volume of thorax increases and lungs expand<br />vertebral column<br />ribs and sternum raised<br />sternum<br />rib<br />ribs and sternum raised<br />rib cage<br />diaphragm contracts and flattens<br />Ribs swing up and increase volume of thorax<br />
    83. 83. PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> Expansion of your lungs causes the air pressure inside them to decrease.</li></ul>Movement of rib cage during inspiration<br />Front view<br />Side view<br />Side view<br />lungs expand, causing air pressure inside lungs to decrease<br />vertebral column<br />ribs and sternum raised<br />sternum<br />rib<br />ribs and sternum raised<br />rib cage<br />diaphragm contracts and flattens<br />Ribs swing up and increase volume of thorax<br />
    84. 84. PG 206<br />Mechanism of Breathing - Inhalation<br /><ul><li> Atmospheric pressure is now higher than the pressure within your lungs. This causes air to rush into your lungs.</li></ul>Movement of rib cage during inspiration<br />Front view<br />Side view<br />Side view<br />lungs expand, causing air pressure inside lungs to decrease<br />air enters lungs<br />vertebral column<br />ribs and sternum raised<br />sternum<br />rib<br />ribs and sternum raised<br />rib cage<br />diaphragm contracts and flattens<br />Ribs swing up and increase volume of thorax<br />
    85. 85. PG 206<br />Mechanism of Breathing - Inhalation<br />What causes air movement into the lungs?<br />Diaphragm contracts<br />External Intercostal Muscles contract<br />Internal Intercostal Muscles Relax<br />Rib cage and sternum move upwards and forward<br />Volume of thoracic cavity increase<br />Pressure of thoracic cavity decrease<br />Lungs expand and air pressure in lungs lower than atmospheric air pressure<br />Air rush in from atmosphere to lungs<br />Biomechanical<br />Physical Parameters<br />
    86. 86. PG 206<br />Mechanism of Breathing - Inhalation<br />Demonstration of Changes in Physical Parameters<br />Volume in thoracic cavity increase<br />Pressure in thoracic cavity decrease<br />Pressure in Lungs > Pressure in thoracic cavity<br />Lungs expand<br />Pressure in lungs drop<br />Atmospheric pressure > Pressure in lungs<br />Air rushes in<br />
    87. 87. PG 207<br />Mechanism of Breathing -Exhalation<br />When you breathe out or exhale, the following events take place:<br />Movement of rib cage during expiration<br />Side view<br />Front view<br />vertebral column<br />sternum<br />rib<br />rib cage<br />
    88. 88. PG 207<br />Mechanism of Breathing - Exhalation<br /><ul><li> Your diaphragm relaxes and arches upwards.</li></ul>Movement of rib cage during expiration<br />Side view<br />Front view<br />vertebral column<br />sternum<br />rib<br />rib cage<br />diaphragm relaxes and arches upwards<br />
    89. 89. PG 207<br />Mechanism of Breathing- Exhalation<br /><ul><li> Your internal intercostal muscles contract while your external intercostal muscles relax.</li></ul>Movement of rib cage during expiration<br />Side view<br />Front view<br />vertebral column<br />sternum<br />rib<br />rib cage<br />diaphragm relaxes and arches upwards<br />
    90. 90. PG 207<br />Mechanism of Breathing - Exhalation<br /><ul><li> Your ribs move downwards and inwards. Your sternum also moves down to its original position.</li></ul>Movement of rib cage during expiration<br />Front view<br />Side view<br />vertebral column<br />ribs and sternum returned to original position<br />sternum<br />rib<br />ribs and sternum raised<br />rib cage<br />diaphragm relaxes and arches upwards<br />Ribs swing down<br />
    91. 91. PG 207<br />Mechanism of Breathing - Exhalation<br /><ul><li> The volume of your thoracic cavity decreases.</li></ul>Movement of rib cage during expiration<br />Front view<br />Side view<br />vertebral column<br />volume of thorax decreases<br />ribs and sternum returned to original position<br />sternum<br />rib<br />ribs and sternum raised<br />rib cage<br />diaphragm relaxes and arches upwards<br />Ribs swing down and decrease volume of thorax<br />
    92. 92. 6 August 2011<br />PG 207<br />Mechanism of Breathing - Exhalation<br /><ul><li> Your lungs are compressed and air pressure inside them increases as the volume decreases.</li></ul>Movement of rib cage during expiration<br />Front view<br />Side view<br />vertebral column<br />lungs are compressed, causing air pressure inside lungs to increase<br />ribs and sternum returned to original position<br />sternum<br />rib<br />ribs and sternum raised<br />rib cage<br />diaphragm relaxes and arches upwards<br />Ribs swing down and decrease volume of thorax<br />
    93. 93. 6 August 2011<br />PG 207<br />Mechanism of Breathing - Exhalation<br /><ul><li> Air pressure within the lungs is now higher than atmospheric pressure. The air is forced out of your lungs to the exterior.</li></ul>Movement of rib cage during expiration<br />Front view<br />Side view<br />air expelled from lungs<br />vertebral column<br />lungs are compressed, causing air pressure inside lungs to increase<br />sternum<br />rib<br />ribs and sternum raised<br />rib cage<br />diaphragm relaxes and arches upwards<br />Ribs swing down and decrease volume of thorax<br />
    94. 94. 6 August 2011<br />Mechanism of Breathing<br />What happens to your intercostal muscles when you are breathing?<br />
    95. 95. PG 207<br />Mechanism of Breathing<br />What happens to your intercostal muscles when you are breathing?<br />R<br />When you inhale, you…<br />Relax your <br />Internal intercostal muscles and <br />Contract your <br />External intercostal muscles<br />I<br />C<br />E<br />
    96. 96. PG 207<br />Mechanism of Breathing<br />What happens to your intercostal muscles when you are breathing?<br />R<br />When you inhale, you…<br />Relax your Internal intercostal muscles and Contract your External intercostal muscles<br />I<br />C<br />E<br />When you exhale, your… <br />External intercostal muscles Relax and your Internal intercostal muscles Contract<br />E<br />R<br />I<br />C<br />
    97. 97. Mechanism of Breathing - Exhalation<br />Demonstration of Changes in Physical Parameters<br />Volume in thoracic cavity decrease<br />Pressure in thoracic cavity increase<br />Pressure in Lungs < Pressure in thoracic cavity<br />Lungs contract<br />Pressure in lungs drop<br />Atmospheric pressure < Pressure in lungs<br />Air rushes out<br />
    98. 98. PG 207<br />Summary of Breathing Mechanism<br />
    99. 99. Learning Objectives<br />By the end of the lesson, you should be able to:<br />State the characteristics and role of alveoli in gaseous exchange<br />Describe the removal of carbon dioxide from the lungs, including the function of carbonic anhydrase.<br />
    100. 100. Breathing and Gaseous Exchange<br />Breathing<br />Gaseous Exchange<br />Between alveolus & blood capillary<br />Oxygen<br />Inhalation<br />(Inspiration)<br />Carbon Dioxide<br />Exhalation<br />(Expiration)<br />Breathing<br />Oxygen<br />Carbon Dioxide<br />Inhalation<br />(Inspiration)<br />Exhalation<br />(Expiration)<br />
    101. 101. Mechanics of Breathing - Expiration<br />What causes air movement out of the lungs?<br />Diaphragm ________________ .<br />External Intercostal Muscles _______________ .<br />Internal Intercostal Muscles _______________ .<br />Rib cage and sternum move _____________ and _____________ .<br />Volume of thoracic cavity ______________ .<br />Pressure of thoracic cavity ____________ .<br />Lungs ___________ and air pressure in lungs ___________ than atmospheric air pressure<br />Air flows from ___________ to _______________ .<br />Biomechanical<br />relaxes<br />relaxes<br />contracts<br />downwards<br />inwards<br />Physical Parameters<br />decreases<br />increases<br />collapse<br />higher<br />lungs<br />atmosphere<br />
    102. 102. Pg 208<br />Breathing and Gaseous Exchange<br />Breathing<br />Gaseous Exchange<br />Between alveolus & blood capillary<br />Oxygen<br />Inhalation<br />(Inspiration)<br />Carbon Dioxide<br />Exhalation<br />(Expiration)<br />Oxygen<br />Carbon Dioxide<br />
    103. 103. Gaseous exchange at alveolus<br />Pg 208<br />
    104. 104. Gaseous exchange<br />Pg 208<br />Alveolus<br />Cells<br />Capillaries<br />
    105. 105. Pg 208<br />Gaseous Exchange- Oxygen<br />How is oxygen taken into the blood capillaries during inspiration?<br />PART 1 – Diffusion<br />Atmospheric air<br />  higherconcentration of oxygen.<br />Deoxygenated blood arriving at the alveoli from the pulmonary artery<br />  a lower concentration of oxygen.<br />This sets up a concentration gradient for oxygen in the alveolar cavity and the blood in the capillaries.<br />
    106. 106. Gaseous Exchange- Oxygen<br />Pg 208<br />How is oxygen taken into the blood capillaries during inspiration?<br />PART 2 – Structure<br />Oxygen thus diffusesfrom the alveolar cavity into the blood capillaries,<br />By dissolving in the thin film of moisture along the alveolar walls.<br />And crossing the one-cell thick membrane of the alveolar wall and blood capillary.<br />
    107. 107. Gaseous Exchange- Oxygen Transport in body<br />Pg 208<br />How is oxygen taken into the blood capillaries during inspiration?<br />PART 3 – Association with Haemoglobin<br />Haemoglobin in red blood cells bind reversibly with oxygen:<br />Oxygen concentration higher in lungs.<br />Hb binds O2.<br />Hb + O2HbO(oxyhaemoglobin)<br />
    108. 108. Pg 209<br />Gaseous Exchange- Carbon Dioxide Transport in body <br />In Actively Respiring Tissues & Blood plasma<br />CO2 diffuses into blood capillaries from actively respiring tissues.<br />CO2 dissolved in blood plasma then combines with water to form carbonic acid:<br />This reaction is catalysed by an enzyme known as carbonic anhydrase.<br />Carbonic acid then dissociates further into hydrogen carbonate anions in blood plasma<br />MOST OF THE CO2 is carried as hydrogencarbonate ions in blood plasma<br />CO2 + H2O H2CO3<br />Carbonic anhydrase(from RBC)<br />H2CO3H+ + HCO3-<br />
    109. 109. Gaseous Exchange- Carbon Dioxide<br />In Lung Tissues<br />Hydrogen carbonate anions in blood recombines with H+ to form carbonic acid.<br />Carbonic acid converted back to CO2 and H2O.<br />CO2 diffuses across capillary and alveolar walls into alveolar cavity.<br />Expelled out of lungs by expiration.<br />
    110. 110. Gaseous Exchange- Carbon Dioxide<br />
    111. 111. Oxygen and carbon dioxide concentration gradient between alveolar air and blood are maintained by:-A continuous flow of blood through blood capillaries- Breathing air in and out of alveoli<br />
    112. 112. Pg 211<br />Comparing Inspired & Expired Air<br />Why is it important to compare inspired and expired air?<br /><ul><li>Because these differences are tell-tale signs of whether something is respiring!
    113. 113. See experiments on page 210-211</li></li></ul><li>Pg 212<br />Stimulus for Breathing<br />What causes the breathing?<br />High concentration of CO2 in blood or alveolar air , NOT concentration of O2.<br />
    114. 114. Test Yourself (Page 213)<br />INCREASE Rate of diffusion of oxygen from the lungs into the blood and of carbon dioxide out of blood into the lungs. <br /> This result in a lower concentration of carbon dioxide in blood or in alveolar air, which lessen the stimulus to breathe.<br />(b) Increasing the carbon dioxide in the air to 8%, even with a 71% increase above normal in oxygen concentration, still increases the rate of breathing greatly. This shows that the stimulus to breathing is carbon dioxide.<br />
    115. 115. Learning Objectives<br />By the end of the lesson, you should be able to:<br />identify on diagrams and name the larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries<br />state the characteristics of, and describe the role of, the exchange surface of the alveoli in gaseous exchange<br />describe the role of cilia, diaphragm, ribs and intercostal muscles in breathing<br />
    116. 116. Learning Objectives<br />By the end of the lesson, you should be able to:<br />describe the effects of constituents of tobacco smoke and its major toxic components – nicotine, tar and carbon monoxide, on human health<br />describe how smoking results in respiratory diseases such as emphysema, bronchitis, and lung cancer<br />
    117. 117.
    118. 118. Smoking & Lung Diseases<br />
    119. 119. Chemicals in Tobacco Smoke<br />Properties of Chemical<br /><ul><li>Addictive Drug
    120. 120. Causes release of hormone adrenaline
    121. 121. Make blood clot easily</li></ul>Effects on body<br /><ul><li>Increase heartbeat and blood pressure
    122. 122. Increase risk of blood clotting in vessels</li></ul>Properties of Chemical<br /><ul><li>Combines with Hb to form carboxyhaemoglobinirreversibly
    123. 123. Increase rate of fat deposition on arterial walls
    124. 124. Damage lining of blood vessels</li></ul>Effects on body<br /><ul><li>Death if concentrations in air increased by 1%
    125. 125. Increased risk of atherosclerosis
    126. 126. Increased risk of blood clotting</li></ul>Chemicals in Tobacco Smoke<br />Nicotine<br />Carbon Monoxide<br />Tar<br />Irritants<br />
    127. 127. Smoking and pregnancy<br /><ul><li>Smoking has immediate effect on unborned child
    128. 128. Cause higher rate of miscarriages, still-births and early death of infants
    129. 129. Pregnant smokers may affect the growth of their unborn child as smoking reduces oxygen available for foetus</li></ul>Passive smoking<br /><ul><li>Non-smokers exposed to cigarette smoke frequently have increased chance of lung cancer</li></li></ul><li>Chronic Bronchitis<br />
    130. 130. Chronic Bronchitis<br /><ul><li>Caused by tiny particles in cigarette smoke
    131. 131. Tracheal and bronchial walls become inflamed leading to over-production of mucus and reduced activity of cilia
    132. 132. Tubes become swollen and clogged by mucus
    133. 133. Collection of mucus in bronchial tubes causes persistent coughing  smoker’s cough
    134. 134. Passageways become narrowed.</li></li></ul><li>Emphysema<br />
    135. 135. Emphysema<br />
    136. 136. Emphysema<br />Healthy Alveolar air sac Alveolar air sac with walls destroyed <br />
    137. 137. Emphysema<br /><ul><li>Condition in which alveolar walls are destroyed
    138. 138. Victim gets very short breath as there is a decrease in alveolar surface for gaseous exchange
    139. 139. Lung tissue is destroyed
    140. 140. Alveoli becomes fewer in number and larger in size than normal</li></li></ul><li>Lung Cancer<br />
    141. 141. Lung cancer<br /><ul><li>Lung cancer may be caused by a certain cancer producing agent in cigarette smoke
    142. 142. The agent causes the rapid abnormal growth of cells in bronchial tube wall
    143. 143. If growth is unchecked or destroyed, cancer may spread to neighbouring cells and organs
    144. 144. Growth also blocks the bronchial tube so that breathing becomes more and more difficult
    145. 145. Life expectancy is usually decreased by smoking, especially if smoking was started at a young age
    146. 146. Smokers who stop smoking increases their life expectancy e.g reduce chances of contracting lung cancer</li></li></ul><li>Respiration in green plants<br />Plants undergo respiration too! Not just human. In fact, any living things must respire to stay alive!<br />
    147. 147. Respiration in green plants<br />Gaseous exchange between plant and environment <br />1. Oxygen<br /><ul><li>Diffuses into intercellular spaces among cells of leaves and stems
    148. 148. Oxygen dissolve in moisture on the walls of the cells and diffuses into the cells
    149. 149. Oxygen diffuses from cell to cell to reach tissues not directly in contact with air</li></li></ul><li>Respiration in green plants<br />2. Carbon dioxide<br />Produced by tissue respiration, diffuse out of the cells through the system of intercellular spaces into the atmosphere via stomata<br />3. Root hair<br />Exchange of oxygen and carbon dioxide between root hair and soil water<br />4. Respiration of plants only detected at night or when plant is in darkness.<br />
    150. 150. Respiration in Green Plants<br />5. Photosynthesis<br /><ul><li>Oxygen released  used partially for tissue respiration
    151. 151. Photosynthesis rate is higher than respiration rate in bright sunlight  oxygen in excess  diffuse out through stomata
    152. 152. Amount of carbon dioxide produced during tissue respiration is insufficient for food-making  more oxygen diffuse into leaf from atmosphere</li></li></ul><li>Respiration vs Photosynthesis<br />

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