When you breathe, your lungs fill up with air, much like a balloon. But balloons require air to be pushed or blown into them. Does air get blown into your lungs like a balloon, or is something else at work in your respiratory system?
The respiratory system consists of many different organs and muscles, including a muscle that sits below the lungs called the diaphragm. This muscle is what allows the lungs to expand and fill with air. But, how does the diaphragm fill the lungs from below? And, where does that air come from that fills the lungs?
To better understand how the respiratory system operates, you can build your own working model of the system with a few ordinary supplies!
Directions:
6. Cut the second straw so that the ends of the two straws are about the same length.
To operate your lung model, gently pinch the center of the stretched balloon and pull it out, away from the cup, then push it back in, towards the inside of the cup. You should see the two smaller balloons inflate when you pull and deflate when you push.