This it is a simple model of lung that will make understand us how these organs work.
What is needed?
Empty soda water bottle of 2 liters
Plastic stock market (a stock market for trash can be used)
Heavy rubber band
What is necessary to do?
We cut the bottle of 2 liters by half. We will use the part of above.
We cut a squared piece of plastic stock-market. We place on the cut part of the bottle and assured with a rubber band.
We inflate the globe to smooth it and we glued it to a drinking straw. Soon we introduce the globe by the mouth of the bottle. We place a little plasticine to assure and that it does not enter air nor leaves.
We cut a sticky tape piece, we only doubled by means gluing until half as it is seen in the photo.
Finally the sticky tape to means of plastic stock-market is thrown out of reach.
How it works?
One gets drunk of the sticky tape and we will notice that the globe is inflated filling of air as a true lung.