Now the reason we have residual volume, the reason that we have these air molecules inside our alveoli is to create a pressure so that our balloon, the alveoli valveolis doesn't actually deflate all the way, doesn't actually collapse. Because if all this residual volume, if all that air was actually removed from our alveolis, we would essentially create a vacuum, an absence of air. And when we have an absence of air molecules, we have no internal pressure. And because no pressure exists to actually push on the walls of our alveolis, in that case the walls would essentially push back and that would create this collapsed structure. So we want to keep that air inside the lungs. We want to have the residual volume of air because we want to keep the bronchioles, the passageways, as well as the individual alveoli from actually collapsing because if they do collapse, that will make the process of breathing very, very difficult.