what happens as you push up the balloon in the lung model

The lung model consists of a bottle, a straw, and balloons. The balloon at the bottom of the bottle represents the diaphragm, which expands and contracts to cause the lungs to fill with air and then empty out again. When you push up the balloon in the lung model, you are simulating the process of exhaling. This is because the diaphragm contracts, pushing all the air out of your lungs. As you push up the balloon, the air inside it is expelled out of the model, just like how air is expelled out of your lungs when you exhale.