The diaphragm separates the contents of the ____ (the ___, ___, and great ___ ___) from the contents of the ____ (the ___, ____, and ___). When it contracts, it tightens and draws downward because it is anchored all along the rim of the ___ ___. This downward movement ____ the volume of the chest cavity, in which the lungs are located on either side of the heart. The ____ volume in the chest produces a ____ in the air pressure in the lungs. Because of the ___ pressure in side the lungs, air from outside the body, which is at a ___ pressure, flows into the lungs to equalize pressure. This is the ___.