Today in class
Today in class looking at lungs we have made some models the green balloon is the lung and the pink balloon is the diaphragm and that is a muscle that controls your breathing and the cup is the chest cavity and the straw is the trachea which help inhale and exhale the air from your lung .
How it works
If you pull down the pink balloon the green balloon inflates and when you let the pink balloon go it deflates and the air goes out the straw.