What causes air to move in or out of the lungs while keeping the lungs in an inflated state?

Answer 1

THEY DO!! There is always air left within lung when we breathe out.... called Dead Air. If we breathed all the air out from our lungs the lung would collapse bc the walls around the air would touch and stick together like when someone puts a few drops of water in between two plates (dishes).... Everytime we breathe in new fresh air it is instantly diluted with the dead air. So we never are able to get the freshness of outside air to reach bloodstream before dilution... I am informed of this information and Im in college, in fact my anatomy and physiology professor was just discussing this exact information yesterday.... I payed attention lol =) thanks hope this helps...

Answer 2

Air doesn't really move in and out at all while the lungs stay full. As the diaphragm pushes upwards, the lungs are mostly emptied and air is expelled; the diaphragm then moves down and fills them again. If the lungs remain inflated, then the diaphragm isn't moving and air exchange doesn't happen.