- Review pupils' understanding of what happens when they breathe and help them to construct a concept map of breathing,
eg oxygen, carbon dioxide, asthma, bronchi, lungs, moisture evaporating from the lungs.
- Ask pupils to feel changes in the chest as they breathe by placing their hands on their ribs and taking a few deep breaths in and out. Ask questions,
eg
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What happened to the chest wall when they breathed in?
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What happened when they breathed out?
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Which required more effort?
- Ask pupils how breathing can vary,
eg when asleep, blowing out candles, playing the trumpet. Discuss how they could measure the volume breathed and which factors might affect lung volume,
eg swimming, playing a brass instrument, body size, asthma.
- Use secondary sources,
eg models, video clips, software simulations, to illustrate how air is drawn into and expelled from the lungs, and help pupils to label simple diagrams.
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- explain that increasing the chest's capacity draws air in, and that reducing the volume of the chest pushes air out
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