The first event in expiration is
A)inter-alveolar pressure increases.
B)elastic tissues of the lungs, thoracic cage, and abdominal organs recoil.
C)air is squeezed out of the lungs.
D)the diaphragm and external intercostal respiratory muscles relax.

Question

Quizplus · Accepted Answer

The first event in expiration is the relaxation of the diaphragm and external intercostal respiratory muscles, which decreases the volume of the thoracic cage and creates an increase in inter-alveolar pressure. This increase in pressure then causes the elastic tissues of the lungs and thoracic cage to recoil, squeezing the air out of the lungs.

The First Event in Expiration Is