In a Puff of Smoke:
Making a Model Lung

Many diseases of the lungs impair their ability to work properly. A common cold, bronchitis, emphysema, and lung cancer reduce the lungs' ability to process air in and out of your body. In this activity you will make a model of your lungs and see how they work.

Procedure

1. Cut off the bottom of a 2-liter soda bottle about 2 inches from the bottom.

2. Obtain a balloon from your teacher. Lower the balloon into the mouth of the soda bottle and stretch the open end of the balloon over the mouth of the soda bottle. The balloon represents your lungs.

3. Obtain a plastic garbage bag. From the bag cut a square 12 × 12 inches.

4. Fold this plastic square twice.

5. Grasp the folded corner and twist about 1 inch of plastic and tape it with the masking tape. This twist will serve as a "handle" for you. Unfold the sheet.

6. Placing the twisted "handle" on the under side, lay the plastic sheet on the table and place the bottle on top of it. Using a rubber band or masking tape, secure the plastic sheet to the bottle. The plastic sheet represents your diaphragm.

7. Hold the bottle and move the plastic sheet out and in. Watch the balloon.