How to Build a Model Lung

Make a model lung for a science class project or for learning more about the lung. This model is based on a plastic bottle transformed into a model.


  1. 1
    Cut a plastic bottle and in two from the top. You will only need the upper part of the bottle.
  2. 2
    Make the tubing for the lungs or the bronchi as they are called. Stick the two smaller straws into the bigger straw. The straws create a Y shape with the bottom of the Y being the bigger straw and the upper part being the 2 smaller straws.
  3. 3
    Make a hole the size of the bigger straw into the bottle cap.
  4. 4
    Guide the Y-shaped tubing through the bottom part of the bottle. The larger straw should come up through the neck of the bottle.
  5. 5
    Fasten the bottle cap and make a seal between the larger straw and the bottle cap. You can use either play-doh or glue.
  6. 6
    Stick the upper part of the Y-shaped tubing into one of your balloons. Be careful not to break the balloon.
  7. 7
    Carefully stretch the balloon's opening onto the neck of the bottle. You should end up with a balloon stretched over a bottleneck, with a tube running through the cap and into the balloon.
  8. 8
    Breathe into the straw to see the lungs in action.


  • This makes a great science project for an at-home or class activity.
  • You could try to make a more accurate model by putting a balloon onto each of the smaller straws, but you may run into problems when trying to inflate said balloons. The smooth and weak structure of a plastic straw prevents an air tight seal from forming.

Things You'll Need

  • Plastic bottle
  • A balloon
  • Three straws - one full size and two of the 1 inch (2.5 cm) variety
  • Glue or any other sealant
  • A tool which can make a hole into a plastic bottle cap

Article Info

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