The lungs are an essential organ to all mammals. It is the organ that allows for gaseous exchange to ensure we get the enough oxygen into our bodies and also exhale the waste products. Today we’re going to find our how lungs work by making a fake lung.
What you will need
- A plastic bottle
- A straw
- An elastic band
- 2 balloons
- Play dough
1. Remove the bottom of your bottle.
2. Tie a knot in one end of a balloon and snip of the fat end.
3. Stretch this end around the bottom of your plastic bottle.
4. Put a straw in the neck of the other balloon and secure tightly with the elastic band but not so that you crush the straw. The air must flow through, so test it with a little bow through the straw to see if the balloon inflates.
5. Put the straw and the balloon into the neck of the bottle and secure with the play dough to make a seal around the bottle – make sure that again, you don’t crush the straw.
Hold the bottle and pull the knot of the ballon at the bottom. What happens?
You should find that the balloon inside the bottle inflates, and that as you let go it deflates.
Why does this happen?
As the knotted ballon is pulled it creates more space inside the bottle. Air then comes down the straw and fills the balloon with some air to fill the space! When you let go of the knot the space no longer exists, so the air from the balloon is expelled making it deflate.
This demonstrates how our lungs work. Air is taken in through the mouth and nose, passes down the windpipe and into our lungs. The diaphragm at the bottom of our chest moves down to create more space. As we breathe out the diaphragm raises again. The knotted balloon represents the diaphragm and the balloon inside the container the lung.