how+breathing+works+21

OBSERVE: Pull down slowly on the stretched balloon. What happens to the balloon inside the cup? The balloon inside inflates.

Push up on the stretched balloon. What happens inside the cup? The balloon inside deflates.

EVALUATE: Is there more or less space inside the cup when you pull down on the large balloon? There is more space on the inside of the cup.

IDENTIFY: When you pull the large balloon down, what fills the extra space in side the cup? The little balloon fills the space. Think more deeply. What else fills the extra space? The balloon was already in there so it's not taking up any more room than it was before. What is filling the extra space?

COMPARE: How is the air pressure in the balloon similar to the air pressure in your lungs? Write down what you think happens when you breathe air into your lungs. When you breath out or pull the big balloon your lungs expand. When you push in or breath in your lungs get smaller.