Constructing a lung model is an excellent way to learn about the respiratory system and how the lungs function. The lungs provide a place for gas exchange between air from the outside environment and gases in the blood. Breathing is controlled by a region of the brain called the medulla oblongata. In the following lung model, structures of the respiratory system will be represented as follows:
- plastic bottle = chest cavity
- plastic tubing = trachea
- Y-shaped connector = bronchi
- balloons inside bottle = lungs
- balloon covering bottom of bottle = diaphragm
Time Required: 20 minutes
- Gather together materials listed under the What You Need section below. You will need scissors, 3 large balloons, 2 rubber bands, electrical tape, a plastic 2 liter bottle, flexible plastic tubing, and a Y-shaped hose connector.
- Fit the plastic tubing into one of the openings of the hose connector. Use the tape to make an airtight seal around the area where the tubing and the hose connector meet.
- Place a balloon around each of the remaining 2 openings of the hose connector. Tightly wrap the rubber bands around the balloons where the balloons and hose connector meet. The seal should be air tight.
- Measure two inches from the bottom of the 2 liter bottle and cut the bottom off.
- Place the balloons and hose connector structure inside the bottle, threading the plastic tubing through the neck of the bottle.
- Use the tape to seal the opening where the plastic tubing goes through the narrow opening of the bottle at the neck. The seal should be air tight.
- Tie a knot at the end of the remaining balloon and cut the large part of the balloon in half horizontally.
- Using the balloon half with the knot, stretch the open end over the bottom of the bottle.
- Gently pull down on the balloon from the knot. This should cause air to flow into the balloons within your lung model.
- Release the balloon with the knot and watch as the air is expelled from your lung model.
- When cutting the bottom of the bottle, make sure to cut it as smoothly as possible.
- When stretching the balloon over the bottom of the bottle, make sure it is not loose but fits tightly.
What You Need
- 3 Large balloons
- 2 Rubber bands
- Electrical tape
- Plastic 2 liter bottle
- Flexible plastic tubing - 8 inches
- Y-shaped hose connector