13.1 Gaseous exchange 13.2 The general plan of the human breathing system 13.3 The process of gaseous exchange in the alveoli 13.4 The mechanism ventilation Mind Map 13 The human breathing system

13.1 Gaseous exchange What is

O2O2 CO 2 Cell Environment take in get rid of 13.1 Gaseous exchange Gaseous Exchange

Cell Organism Respiratory Surface 13.1 Gaseous exchange O2O2 CO 2 Environment get rid of take in

Organism takes in O 2 from the surroundings & get rid of CO 2. This exchange of gases is called gaseous exchange Gaseous exchange  Definition:

13.2 The general plan of the human breathing system What is the pathway for air to go into the human breathing system?

13.2 The general plan of the human breathing system

NostrilNasal cavityEpiglottisLarynxPharynx 13.2 The general plan of the human breathing system

cell Cilium [Cilia] Ciliated 13.2 The general plan of the human breathing system Nasal cavity

cell Cilium [Cilia] Ciliated 13.2 The general plan of the human breathing system Motion of cilia

Ciliated epithelium 13.2 The general plan of the human breathing system

Mucus- secreting cell Mucus Particles

13.2 The general plan of the human breathing system Mucus- secreting cell Mucus Particles

13.2 The general plan of the human breathing system Air

13.2 The general plan of the human breathing system Air Trapped particles are swept by beating cilia Towards the pharynx Mucus traps the particles Mucus moistens the air

13.2 The general plan of the human breathing system Air Can keep the air warm Cool Air Warm Blood vessels

13.2 The general plan of the human breathing system Nasal cavity the incoming air filters moistens warms

13.2 The general plan of the human breathing system Breathing System Digestive System Pharynx Junction

Larynx 13.2 The general plan of the human breathing system

Epiglottis

13.2 The general plan of the human breathing system Close trachea Prevent food from entering the trachea when you swallow Epiglottis

13.2 The general plan of the human breathing system Membranes Vibrate to produce sound Vocal cords

13.2 The general plan of the human breathing system

Larynx Trachea 13.2 The general plan of the human breathing system

supported by C-shaped cartilage

13.2 The general plan of the human breathing system Oesophagus Trachea

C-shaped cartilage Ciliated epithelium Filter, moisten and warm incoming air Keep trachea open 13.2 The general plan of the human breathing system Oesophagus Trachea

13.2 The general plan of the human breathing system Trachea From larynx Bronchus To

13.2 The general plan of the human breathing system Trachea Bronchus Bronchiole Alveolus

13.2 The general plan of the human breathing system Plural:Alveoli Alveolus

Capillary 13.2 The general plan of the human breathing system Alveolus

13.2 The general plan of the human breathing system Alveolus Capillary

13.2 The general plan of the human breathing system Alveolus Capillary

13.2 The general plan of the human breathing system Air InAir Out Alveolus is the site for gaseous exchange

Experiment 13.1 To examine of the breathing system of a dissected mammal You will be shown a dissected mammals (a rat or rabbit) The general plan of the human breathing system Examine the specimen carefully. Identify as many breathing organs as you can.

13.2 The general plan of the human breathing system larynx trachea bronchus rib lung diaphragm

Experiment 13.2 To examine the trachea and the lungs of a pig Examine a pig’s lungs and trachea obtained from a butcher’s shop. Caution: Clean the lungs before the experiment. Wear disposable gloves The general plan of the human breathing system

Question 1: What colour are the lungs? Why do they have such a colour? Answer 1: The lungs are pink because they contain many capillaries. Question 2: Press them gently with your fingers. What do they feel like? Why do they feel like that? Answer 2: It gives a spongy feeling. It is because the lungs are made up of alveoli which are filled with air Experiment 13.2 To examine the trachea and the lungs of a pig 13.2 The general plan of the human breathing system

Question 3: What is the name of the structure that covers the surface of the lungs? What is its function? Answer: The outer covering of the lungs is the pleural membrane which secretes fluid to reduce friction. This is why the surface of the lungs is slippery. Experiment 13.2 To examine the trachea and the lungs of a pig 13.2 The general plan of the human breathing system

Question 4: Squeeze the trachea with your fingers. What does it feel like? Why does it feel like that? Answer 4: It has an elastic feeling as the wall of the trachea is stiffened by C-shaped cartilages. Question 5: Attach the trachea to a pump. Make sure that the joint is air- tight. What happens to the lungs when air is pumped in and out of the lungs? Explain your observations. Answer 5: The lungs inflate as air is pumped into them. Experiment 13.2 To examine the trachea and the lungs of a pig 13.2 The general plan of the human breathing system

13.3 The process of gaseous exchange in the alveoli

Alveoli

13.3 The process of gaseous exchange in the alveoli Red blood cell Higher oxygen concentration Lower oxygen concentration in blood Moisture

13.3 The process of gaseous exchange in the alveoli Red blood cell O 2 in inhaled air Across walls of alveolus and capillaries 1 Dissolve Diffusion 2 To the 3 Moisture

13.3 The process of gaseous exchange in the alveoli Red blood cell O2O2 Oxyhaemoglobin + Haemoglobin Transport to other parts of the body O2O2 O2O2

13.3 The process of gaseous exchange in the alveoli CO 2 HCO 3 - (hydrogencarbonate ion) CellCell Transported in the plasma

13.3 The process of gaseous exchange in the alveoli higher CO 2 concentration in blood higher CO 2 concentration in blood 2 lower CO 2 concentration in mucus lower CO 2 concentration in mucus 1

13.3 The process of gaseous exchange in the alveoli Diffusion 2 Across walls of alveolus and capillaries CO 2 in exhaled air Diffusion 3

CellCell Lung Air out 13.3 The process of gaseous exchange in the alveoli Dissolve in moisture 1 1 Diffuse across the wall of alveoli & blood capillaries 2 2 Combines with Hb to form oxyhaemoglobin 3 3 Air in O 2 diffuses into the cells 4 4 Diffuse across the wall of blood capillaries & alveoli 4 4 HCO 3 - is carried by plasma 3 3 CO 2 diffuses into the blood 2 2 Cells produce CO Transportsystem O2O2 CO 2

CellCell Lung Air out 13.3 The process of gaseous exchange in the alveoli Air in Transportsystem O2O2 CO 2 respiration Gaseous exchange breathing

13.3 The process of gaseous exchange in the alveoli

Surface area for diffusion 1 1 highly folded

alveoluscapillary The process of gaseous exchange in the alveoli O 2 concentration in …. No net movement of oxygen! No net movement of oxygen! The alveoli are covered by numerous capillaries 2 2

alveoluscapillary 13.3 The process of gaseous exchange in the alveoli O 2 concentration in The alveoli are covered by numerous capillaries 50 O 2 Transport away 50 O 2 Transport away 50 O 2 Transport away 50 O 2 Transport away 50 O 2 Transport away 2 2

alveoluscapillary 1000 O 2 concentration in * Maintain a great concentration gradient High rate of diffusion 13.3 The process of gaseous exchange in the alveoli The alveoli are covered by numerous capillaries 2 2

One-cell thick Provides a short distance for diffusion Can dissolve gases for diffusion 13.3 The process of gaseous exchange in the alveoli Both walls of alveolus and capillary are 4 4 Moist 3 3

Alveolar wall is one-cell thick ImportanceImportance Short distance for diffusion Large surface area Steep concentration gradient Dissolve gases Highly folded Numerous capillaries The walls are moist 13.3 The process of gaseous exchange in the alveoli FeaturesFeatures Adaptations of alveoli for gaseous exchange

MoreLess MoreLess Same VariableSaturated VariableHigher Used by the Cells Produced by the Cells Not used by the Cells Evaporation from the respiratory surfaces Warmed by the higher body Temperature Oxygen Carbon dioxide Nitrogen Water vapour Temperature 13.3 The process of gaseous exchange in the alveoli

Lung Intercostal muscles Two pleural membranes Rib Diaphragm 13.3 The process of gaseous exchange in the alveoli

pleural membranes 13.3 The process of gaseous exchange in the alveoli

Pleural membranes Pleural fluid 13.3 The process of gaseous exchange in the alveoli secrete

Reducing friction when the pleural membranes rub against each other during breathing Lubricate the pleura Pleural membranes Pleural fluid 13.3 The process of gaseous exchange in the alveoli

Pleural membranes Intercostal muscle Diaphragm Nostril Nasal cavity Pharynx Larynx Trachea Bronchus Bronchiole Alveolus Rib 13.3 The process of gaseous exchange in the alveoli

Experiment 13.3 To compare the oxygen content of inhaled and exhaled air 13.3 The process of gaseous exchange in the alveoli gas jar water trough rubber tube 1. Collect a jar of exhaled air over water. Cover the jar with a cover plate. 2. Collect a jar of inhaled (atmospheric) air. Cover the jar with another cover plate.

Experiment 13.3 To compare the oxygen content of inhaled and exhaled air 13.3 The process of gaseous exchange in the alveoli burning spoon burning candle gas jar 3. Use a burning spoon to put a burning candle into the gas jar of exhaled air. Record the time of burning of the candle inside the gas jar. 4. Now put a burning candle into the gas jar of inhaled air. Record the time of burning of the candle inside the gas jar.

Question 1: In which jar does the candle burn longer? Answer 1: The candle burns longer in the jar of inhaled air. Experiment 13.3 To compare the oxygen content of inhaled and exhaled air 13.3 The process of gaseous exchange in the alveoli burning spoon burning candle gas jar

Question 2: Which gas must be present for the candle to burn longer? Answer 2: Only oxygen can support combustion. Experiment 13.3 To compare the oxygen content of inhaled and exhaled air 13.3 The process of gaseous exchange in the alveoli Question 3: What do the results tell you about the amount of this gas in inhaled and exhaled air? Answer 3: Inhaled air contains more oxygen than exhaled air.

Question 4: Does the flame go out immediately when the burning candle is put into the gas jar of exhaled air? What does this show? Answer: The flame does not go out immediately, showing that exhaled air also contains oxygen. Experiment 13.3 To compare the oxygen content of inhaled and exhaled air 13.3 The process of gaseous exchange in the alveoli

Experiment 13.4 To compare the carbon dioxide content of inhaled and exhaled air 13.3 The process of gaseous exchange in the alveoli 1. Set up the apparatus as shown on the right. 2. Breathe in and out gently through the rubber tubing. Do not breathe too hard. Keep doing this until the lime water in one of the boiling tubes has changed colour. to mouth rubber tubings boiling tubes lime water

Experiment 13.4 To compare the carbon dioxide content of inhaled and exhaled air 13.3 The process of gaseous exchange in the alveoli Question 1: In which tube did bubbles appear when you breathe out? Answer 1: Tube B. Question 2: In which tube did bubbles appear when you breathe in? Why? Answer 2: Tube A. The inhaled air enters tube A before it goes into the lungs.

Question 3: What happened to the lime water in tubes A and B? Answer 3: The lime water in tube A remained clear while that in tube B turned milky The process of gaseous exchange in the alveoli Question 4: What do the results tell you about the amount of carbon dioxide in inhaled air and exhaled air? Answer 4: Carbon dioxide content in exhaled air is higher than that in inhaled air. Experiment 13.4 To compare the carbon dioxide content of inhaled and exhaled air

Experiment 13.4 To compare the carbon dioxide content of inhaled and exhaled air 13.3 The process of gaseous exchange in the alveoli Question 5: What solution can you use instead of lime water? If this is used, what changes would you expect in tubes A and B? Answer: Hydrogencarbonate indicator solution can be used instead of lime water. It changes from red to yellow when more carbon dioxide dissolves in it. Thus it remains red in tube A and turns yellow in tube B.

13.4 The mechanism of ventilation The mechanism of ventilation and gaseous exchange

InOut InspirationExpiration (Ventilation) 13.4 The mechanism of ventilation

backbone rib 13.4 The mechanism of ventilation intercostal muscle head sternum

13.4 The mechanism of ventilation Intercostal muscles contract 1 Ribs move upwards 2 Inspiration & outwards Chest Volume [Before inspiration]

13.4 The mechanism of ventilation Inspiration

13.4 The mechanism of ventilation Inspiration

13.4 The mechanism of ventilation Inspiration

13.4 The mechanism of ventilation Inspiration

13.4 The mechanism of ventilation Inspiration

13.4 The mechanism of ventilation Inspiration

13.4 The mechanism of ventilation Inspiration

13.4 The mechanism of ventilation Chest Volume [After inspiration] Intercostal muscles contract 1 Ribs move upwards 2 Inspiration & outwards Chest volume increases 3

Difference? Diaphragm becomes flattened 13.4 The mechanism of ventilation Inspiration Chest volume increases

13.4 The mechanism of ventilation Inspiration Chest volume increases and smaller than atmospheric pressure Chest pressure decreased air moves in

Air rush in Intercostal muscles & diaphragm muscles Intercostal muscles & diaphragm muscles Chest Volume Rib Cage Diaphragm Results in Air pressure in lungs Contract Relax Move upwards & outwards Move downwards & inwards Flattened Dome-shaped Increases Decreases Lower than atmosphere Lower than atmosphere Higher than atmosphere Higher than atmosphere Air rush out 13.4 The mechanism of ventilation

Experiment 13.5 To study the change in breathing rate during exercise using a data logger You should record the following data: 1.Breathing rate before exercise 2.Breathing rate during exercise 3.Breathing rate after exercise

time (seconds) lung volume (cm 3 ) Rate of Breathing No. of breaths per minute 6 breaths 20 s = X breaths 60 s X=18 breaths / min 13.4 The mechanism of ventilation

time (seconds) lung volume (cm 3 ) = 500cm 3 Depth of Breath Volume of air breathed in per breath The mechanism of ventilation

Rate of Breathing No. of breaths Depth of Breath Volume of air breathed inper breath per minute The mechanism of ventilation

time (seconds) lung volume (cm 3 ) time (seconds) lung volume (cm 3 ) At rest During exercise Depth of breathRate of breathing 13.4 The mechanism of ventilation

During exercise Depth of breathRate of breathing 13.4 The mechanism of ventilation Amount of O 2 taken in O 2 supply to musclesRate of respiration of muscles Energy supplied for muscular contraction

During exercise 13.4 The mechanism of ventilation Amount of CO 2 produced Rate of respiration of muscles Depth of breathRate of breathing To remove more CO 2

Gaseous exchange in human involves for the rate and depth increase when doing involve the movement of consists of the exchange of by breathing system 1. nasal cavity 2. pharynx 3. larynx 4. trachea 5. lungs bronchibronchiolesalveoli ventilation oxygen inspiration expiration carbon dioxide 1. diaphragm 2. Ribs and sternum exercise Mind Map