Normal exhalation (expiration) is due to
A) relaxation of inhalation (inspiratory) muscles.
B) the inward pull of surface tension due to the film of alveolar fluid.
C) recoil of elastic fibers in the lungs.
D) all of these choices.

Question

Quizplus · Accepted Answer

Normal exhalation is a passive process involving the relaxation of inspiratory muscles, the inward pull of surface tension due to alveolar fluid, and the recoil of elastic fibers in the lungs. All these factors contribute to the process of expiration.

Normal Exhalation (Expiration) Is Due to