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