If you belljar model has a rubber stopper in the top you can

If you bell-jar model has a rubber stopper in the top, you can use it to demonstrate the effects of a pneumothorax on lung tissue. A pneumothorax generally is caused by a tear in the pleural membranes that allows air to enter the pleural cavity. With the diaphragm flat and the lungs (balloons) inflated, loosen the rubber stopper. What happens to the lungs? Why?

Solution

Without immediate medication, he will die.

If the rubber stopper was loosen and the balloons inflate, the air pressure in the bell jar decreases. This higher air pressure caused the balloons to inflate.

As the air pressure in the thoracic increases ( bell jar) increases, air is forced out of the lungs. As the air pressure in the cavity decreases the ambient air will rush into the lungs.