From Today’s Science Lesson That I Did

 

Take a Breath

Ellie, after you read this sentence, take a big breath in, and then let it out.

Did you feel your chest expand and shrink? It does that about 20 THOUSAND times a day, using air pressure to bring air in and out of your body. Let’s find out how by using your vacuum chamber!

1. Ask Catrina to help you blow up one of the balloons in your kit about halfway and then tie it closed. It should be about half as wide as the bottom of the jar.

2. Put the balloon onto the base of the chamber and then close the chamber by putting the jar back on top.

3. Pump the air out of the vacuum chamber.

What happens to the balloon? Does it get bigger, stay the same size, or get smaller?

Yep, it gets bigger! So how is that like your lungs? 

When you breathe in, the muscles in your chest expand your lungs, making them bigger. That makes the air in your lungs less packed together. That means the pressure of the air in your lungs drops, making it low pressure. Higher pressure air from outside rushes in to fill up that extra space. Now your lungs are filled with lots of air!

This is like when you pumped the air out of the chamber. The balloon acts like your lungs, getting bigger and making room for more air to be in it.

Now undo the clip on the vacuum chamber’s hose and let the air back in. What happens to the balloon now?

Right again – it gets smaller! This is what happens to your lungs when you breathe out. Your muscles squeeze your lungs to make them smaller. This squishes the air in your lungs tighter together, making it high pressure air. This high pressure air rushes out to the air that’s less packed together outside your body. 

Wondering why the air moves like that? Because air likes to keep the pressure balanced! That means everything is at the same pressure. If it’s not balanced, any high pressure air will flow into the low pressure air to make things equal. 

Imagine another air pressure party, but this time it has two rooms. One is packed full of air, and the other room is almost empty. Then someone opens a door between the rooms. What happens? 

What would YOU do if you were  in the full room? Would you want to bring stuff from the other room in, making your room even more packed? No! You’d want to move into the emptier room to have more space to dance!

Well that’s what air does too, it moves from one place to another until both are equally full. With breathing, that means it moves between the outside air and your lungs.

Whew, you made it all the way through! Now take a deep breath and thank air pressure for helping you breathe! 🙂