Which of the following does NOT occur during expiration when a person is breathing quietly?
A)The size of the thoracic cavity is reduced.
B)The intra-alveolar pressure becomes greater than the atmospheric pressure.
C) Air flows out of the lungs.
D) The expiratory muscles contract.

Question

Quizplus · Accepted Answer

During quiet expiration, the expiratory muscles (such as the internal intercostals or abdominal muscles) do not contract. Instead, expiration occurs passively as the size of the thoracic cavity is reduced, causing the intra-alveolar pressure to become greater than atmospheric pressure, leading to the outflow of air from the lungs.

Which of the Following Does NOT Occur During Expiration When