Quiet expiration requires the
A)contraction of the diaphragm and the internal intercostals only.
B)contraction of the diaphragm and the external intercostals only.
C)relaxation of all the respiratory muscles.
D)contraction of the diaphragm only.

Question

Quizplus · Accepted Answer

Quiet expiration is the passive process of exhaling air that does not require any active muscular effort. Instead, it occurs due to the relaxation of all the respiratory muscles, including the diaphragm, external intercostal muscles, and abdominal muscles. As the chest cavity decreases in size, the air is pushed out of the lungs, leading to quiet expiration. Therefore, option (C) is the best choice as it correctly describes the mechanism of quiet expiration.

Quiet Expiration Requires the