Mike takes deep breaths, and knows that his chest volume is fairly sizable. Considering his chest size, the air pressure outside the lungs, compared to the air pressure inside, is
lower higher
A B
During inhalation, because the chest volume is larger, the air pressure inside the lungs is lower than the air pressure outside.
air pressure inside lungs
larger
lower
MORE
LESS
chest volume
higher
lower
air pressure
air pressure
air pressure