Which one of the following is NOT True of inspiration?
A) Contraction of the diaphragm muscle helps increase the size of the thoracic cavity.
B) Relaxation of the external intercostal muscles helps increase the size of the thoracic cavity.
C) Increased intrapulmonary volume causes inhaled gases to spread out.
D) The decreased gas pressure produces a partial vacuum that forcibly sucks air in.
E) Air continues to move into the lungs until intrapulmonary pressure equals atmospheric pressure.

Question

Quizplus · Accepted Answer

Relaxation of the external intercostal muscles does not help increase the size of the thoracic cavity; rather, it is their contraction along with the diaphragm that increases thoracic volume during inspiration. Relaxation of these muscles typically occurs during expiration.

Which One of the Following Is NOT True of Inspiration