See Your Lungs in Action (61 Brilliant Biology Experiments)

You will need:

1. Clear 2 litre plastic bottle (empty)
2. Scissors
3. 2 straws
4. 2 large balloons
5. Electrical tape
6. Rubber bands
7. Plastic bag

Follow this experiment to make a working model of the lungs and their function in our respiratory system.

INSTRUCTIONS

1. Ask an adult to help cut the base off a plastic bottle using scissors.
2. Take a straw and insert it all the way into the balloon.
3. Tape the area where the balloon opening meets the straw.
4. Repeat the same procedure with the other balloon and straw.
5. Insert both straws into the bottle.
6. Tape the straws at the opening of the bottle to seal it.
7. No air should be able to get through between the straws and the bottle.
8. Secure the base opening of the bottle with a plastic bag and rubber band.
9. Leave the bag slightly loose and stick a piece of tape on it to act as a handle.

RESULT

When you pull the plastic bag covering outward, the ‘lungs’ (balloons) expand, and when the plastic bag is pushed back into the bottle, the ‘lungs’ contract. We always assume that our lungs pull air into our chest. Actually it is the muscle known as the diaphragm (plastic bag) which pushes air into our lungs.