Worksheet B5d 1 The respiratory system You are going to use models, charts, a short video and page 26 of the student book to learn about the respiratory system. 1 2 Use the following words to label the diagram below. air sac bronchiole bronchus diaphragm lung pleural membrane rib trachea intercostal muscles List the parts of the respiratory system that: a molecule of oxygen passes through before entering the blood, starting with the trachea Trachea ______________________________________________________________ a molecule of carbon dioxide passes through after leaving the blood, starting with an air sac Air sac _______________________________________________________________ Worksheet B5d 2 How we breathe in and out The action of the diaphragm Look at the bell jar with a rubber sheet. It is a model of our lungs, chest and diaphragm. If you pull and push on the rubber sheet you can see how the lungs are filled and then emptied of air. 1 If the rubber sheet is pushed downwards, this increases the volume inside the chest. What happens to the balloons? ___________________________________________________________________________ 2 If the rubber sheet is pushed upwards, this decreases the volume inside the chest. What happens to the balloons? ___________________________________________________________________________ Worksheet B5d 2 Continued The action of the diaphragm and intercostal muscles The diagram below shows inhalation and exhalation. Complete the following sentences to explain how we breathe in. 3 The intercostal muscles between the _______________ contract. 4 This moves the ribs _______________ and _______________. 5 At the same time, the diaphragm muscle _______________ and moves _______________. 6 The volume of air inside the chest _______________. This decreases the pressure inside the chest. The air pressure outside the chest is higher so air enters the lungs. Complete the following sentences to explain how we breathe out. 7 The intercostal muscles _______________. 8 The ribs are moved _______________ and _______________. 9 At the same time, the diaphragm muscle _______________ and moves _______________. 10 The volume of air inside the chest __________________. This increases the pressure inside the chest. The air pressure outside the chest is now lower so air leaves the lungs. Worksheet B5d 3 Breathing in and out You will need: two conical flasks two bungs rubber tubing fresh limewater or bicarbonate indicator new or sterilised mouthpieces Method 1 Pour equal amounts of fresh limewater or bicarbonate indicator into two conical flasks labelled A and B. 2 Join the flasks with rubber tubing. 3 Gently breathe in and out through the clean mouthpiece. 4 Repeat breathing in and out until there is a change in the content of one of the flasks. Health and safety! Take care – if you breathe in too deeply, you could suck up the limewater. Conclusion 1 Which flask are you breathing in (inhaling) through? Flask _______________ 2 Which flask are you breathing out (exhaling) through? Flask _______________ Worksheet B5d 3 Continued 3 Explain what happened to the limewater/indicator in flask B. ___________________________________________________________________________ 4 Explain what happened to the limewater/indicator in flask A. ___________________________________________________________________________ 5 Which flask showed the presence of the most carbon dioxide? ___________________________________________________________________________ 6 Where had this carbon dioxide come from? ___________________________________________________________________________ 7 Which flask showed the presence of the least carbon dioxide? (Air contains 0.04% carbon dioxide) ___________________________________________________________________________ B5d 1 Technician’s notes Class demonstration – Respiration by peas Equipment: germinating peas dead, sterilised peas (sterilised by using a fungicide or alcohol, so they will not decay and produce heat) vacuum flasks clamps and clamp stands cotton wool thermometers Support the flasks with clamp stands and clamp them upside down to prevent heat loss from neck. The germinating peas respire, releasing energy, some of which is ‘lost’ as heat. Low demand activities diagrams of fish gills or real fish gills models and/or charts of respiratory organs access to computers access to Internet short flash video from www.breatheinfo.com/about_asthma/is_it.asp Class demonstration – How we breathe in and out Equipment: bell jar two balloons attached to a Y piece rubber sheet firmly attached across the bottom of the bell jar B5d 1 Continued Class experiment – Breathing in and out Equipment: two conical flasks two bungs rubber tubing supply of fresh limewater or bicarbonate indicator new or sterilised mouthpieces Health and safety! New or sterilised mouthpieces must be used for each student. They can be sterilised in Milton for 30+ minutes. Class demonstration – Lung capacities Equipment: graduated bell jar two inverted mortars sink water screw clip new or sterilised mouthpieces or lung volume bag kit Health and safety! Check the students’ medical histories for conditions such as asthma before they take part in this demonstration. New or sterilised mouthpieces must be used for each student. They can be sterilised in Milton for 30+ minutes. Class demonstration – Exchange of air You will need: tank spirometer (this is expensive (£800) but it might be used for classes in the sixth form) or pocket spirometer (this is a simpler and cheaper version at £130) Health and safety! Use of spirometers must be closely supervised by the teacher. B5d 1 Answers Worksheet B5d 1 – The respiratory system 1 Trachea Pleural membrane Lung Bronchus Intercostal muscles Bronchiole Rib Air sac Diaphragm 2 a Trachea bronchus bronchiole air sac Air sac bronchiole bronchus trachea Worksheet B5d 2 – How we breathe in and out 1 Balloons inflate 6 Increases 2 Balloons deflate 7 Relax 3 Ribs 8 Down, in 4 Out, up 9 Relaxes, up 5 Contracts, downwards 10 Decreases Worksheet B5d 3 – Breathing in and out 1 Flask A 2 Flask B 3 Turns milky; changes colour because of the presence of carbon dioxide 4 Only slightly milky; faint change of colour or no changes 5 Flask B 6 From respiration in body cells such as muscles 7 Flask A
