Procedure 1. Attach the balloon to the end of the straw that fits inside the wash bottle, and secure it with a rubber band. The balloon will act as the lung.

 2. While gently squeezing the bottle, replace the top and secure it tightly. 

3. Squeeze the bottle and record what happens to the balloon. Release the bottle and observe what happens. (I performed the procedure, the balloon deflated when bottle is squeezed and inflated when the bottle is released)

Questions: 1. What happens to the balloon? Why?

 2. What would happen if the seal at the base of the bottle leaked? 

3. What causes a collapsed lung?

 4. Is a collapsed lung functional? Why or why not?