Do you know our ability to exhale Carbon dioxide and inhale Oxygen is nothing but a miracle.
Did you know there has to be pressure difference between our lungs and environment that allows us to breath?
When air pressure in our lungs is lower than our atmosphere, air comes into the lungs.
A higher pressure in the lungs as you guess helps us with exhaling.
Yes, we are fearfully and wonderfully made-Ps.139:14
Source: http://people.eku.edu/ritchisong/301notes6.htm
How Great is our God!