During expiration, air will leave the lungs when the pressure inside the lungs is
- A.equal to the atmospheric pressure
- B.less than the atmospheric pressure
- C.more than the atmospheric pressure
- D.when the diaphragm contracts
Show answer
Air always moves from a region of higher pressure to one of lower pressure, so it flows out of the lungs only when the pressure inside them rises above that of the outside air.
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