When we are not active, each of us breathes about ten times every minute. Surprisingly, our lungs have no muscles of their own. So, how can they do the work of breathing?

The work is done by muscles in the walls and bottom of the chest. When these muscles tighten, they make the space inside the chest larger. This lets air rush into the lungs. When the muscles relax, the space becomes smaller and air moves out of the lungs. Try to breathe in and out without moving your chest. Is it possible?

Try This!

You can make a model of the way your lungs work. You will need a medium-sized clear plastic bottle (a dishwashing soap bottle works well), scissors and 2 medium-sized balloons.

1. Have an adult help you cut off the bottom half of the bottle. the top part of the bottle should be about 6 inches (15 cm) tall.
2. Slide a balloon into the mouth of the bottle and roll the open end over the top edge of the bottle. This will be the "lung in your model.
3. Cut off the top of the other balloon. Tie a knot in the bottom of the remaining piece. Slide the cut end around the bottom of the bottle.
4. Pull the bottom balloon carefully downward. What happens to the "lung" balloon? This is similar to what happens when you breathe in. Gently squeeze the sides of the bottle and push the bottom balloon into the space in the bottle. Now what happens?

Coughing and sneezing help clean out your airways. Can you make your lung model cough or sneeze?

It's In the Air

Excuse me please, I've got to sneeze.
I feel it coming on!
Is it the dust in this old house
that makes it feel so strong?
Or maybe pollen from the plants, released in spring and fall?
Or spores produced by all the mold on our damp basement wall?
Or maybe pepper from the can I spilled all over there!
Achoo, achoo, achoo, achoo -- there's something in the air!