The force responsible for normal expiration is supplied by the
A)diaphragm.
B)external intercostal muscles.
C)elastic recoil of tissues and surface tension.
D)contraction of smooth muscles in air passages.

Question

Quizplus · Accepted Answer

During normal expiration, the elastic recoil of lung tissues and surface tension between the alveolar walls help to deflate the lungs, providing the force for air to move out of the lungs. The diaphragm and external intercostal muscles are used during inspiration, while smooth muscles in the air passages are used during forced expiration.

The Force Responsible for Normal Expiration Is Supplied by the