Model-making: Make a model of the respiratory system to demonstrate inhalation and exhalation.
Apparatus Bell jar or large plastic bottle with bottom cut off One-holed rubber stopper to fit bell jar or bottle Y-shaped glass tubing Two balloons Strong tape Rubber sheet – a rubber swimming cap works well
Method 1. Assemble the apparatus as shown in the diagram. 2. Make sure that the balloons and the rubber sheet are securely attached.
3. Pull the rubber sheet down – note what happens to the balloons. 4. Push the rubber sheet back up – note what happens to the balloons.
Balloons
Rubber sheet
Fig. 8 A model of the respiratory system.
Questions 1. What does the Y-shaped glass tubing represent? 2. What do the balloons represent? 3. What does the rubber sheet represent? 4. What happens when the rubber sheet is pulled down? 5. Based on the model, outline how inhalation / exhalation occur in humans. 6. This model does not demonstrate one action during inhalation or exhalation. What is this action?