[Biology]

[Puff Power]

[Theory:]
There are two ways of breathing air into your lungs. One way is by using your chest muscles, and the other way is by using your stomach muscles. Lie down on your back and put a hand on your stomach. Try breathing without moving your hand (this uses your chest muscles). Now when you breathe, try moving your hand as much as possible (this uses your stomach muscles). Which kind of breathing do you think puts the most air in your lungs? Try this test and find out!

[Materials:]

[Procedure:]
  1. Using the measuring cup, measure how much water the smaller bottle can hold.
  2. Fill the large water jug about half full of water, and fill the smaller plastic bottle to the brim.
  3. Cover the mouth of the smaller bottle with your hand and tip it upside down. Lower it into the jug until the mouth of the bottle is underwater, then remove your hand.
  4. Slip one end of the plastic tube underwater and into the mouth of the smaller bottle.
  5. Breathe out all the air in your lungs. Refill your lungs, using only your chest muscles, then blow all the air in your lungs through the tube, into the bottle.
  6. Slide one hand over the mouth of the bottle, then turn it upright and place it on the ground.
  7. The amount of air that you breathed will be the amount of air in the bottle. Take the masking tape and mark where the level of the water is. Now use the measuring cup to measure how much water was in the bottle. Subtract the volume of water in the bottle from the total volume of the bottle to determine the amount of air you breathed. Record this amount.
  8. Repeat the experiment filling your lungs only using your stomach muscles. Record this amount and compare to the first part of the experiment.

[Conclusions:]
When you use your chest muscles to fill your lungs, you are only filling the upper part of your lungs. When you use your stomach muscles, you are filling the bottom part of your lungs. If you were to use both your stomach muscles and your chest muscles to fill your lungs, you would get the biggest possible puff power!

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Produced by Galactics.
Comments: galactics@spacesim.org.
Last updated on 14 August 1998.