1Use the Following Words to Label the Diagram Below
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.
1Use the following words to label the diagram below.
air sacbronchiolebronchusdiaphragmintercostal muscles
lungpleural membranerib trachea
2List 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.
1If the rubber sheet is pushed downwards, this increases the volume inside the chest.
What happens to the balloons?
______
2If 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.
3The intercostal muscles between the ______contract.
4This moves the ribs ______and ______.
5At the same time, the diaphragm muscle ______and moves ______.
6The 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.
7The intercostal muscles ______.
8The ribs are moved ______and ______.
9At the same time, the diaphragm muscle ______and moves ______.
10The 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
1Pour equal amounts of fresh limewater or bicarbonate indicator into two conical flasks labelled
A and B.
2Join the flasks with rubber tubing.
3Gently breathe in and out through the clean mouthpiece.
4Repeat 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
1Which flask are you breathing in (inhaling) through?
Flask ______
2Which flask are you breathing out (exhaling) through?
Flask ______
Worksheet B5d 3 Continued
3Explain what happened to the limewater/indicator in flask B.
______
4Explain what happened to the limewater/indicator in flask A.
______
5Which flask showed the presence of the most carbon dioxide?
______
6Where had this carbon dioxide come from?
______
7Which 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
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 asthmabefore 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) orpocket 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
Lung
Intercostal muscles
Rib
Diaphragm
Pleural membrane
Bronchus
Bronchiole
Air sac
2
aTrachea bronchus bronchiole air sac
Air sac bronchiole bronchus trachea
Worksheet B5d 2 – How we breathe in and out
1Balloons inflate
2Balloons deflate
3Ribs
4Out, up
5Contracts, downwards
6Increases
7Relax
8Down, in
9Relaxes, up
10Decreases
Worksheet B5d 3 – Breathing in and out
1Flask A
2Flask B
3Turns milky; changes colour because of the presence of carbon dioxide
4Only slightly milky; faint change of colour or no changes
5Flask B
6From respiration in body cells such as muscles
7Flask A