posted by Renee .
Which of the following is the muscle action that results in exhalation and causes the air pressure inside the lungs to be higher than outside the chest
a) Contraction of internal intercostals
b) Relaxation of the diaphragm
c) Contraction of the diaphragm
d) Relaxation of the external intercostals
I choose C?
Yes, when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. This increases the space in your chest cavity, into which your lungs expand.