During expiration, relaxation of the diaphragm and external intercostals
A) increases the volume of the thoracic cavity.
B) increases the pressure in the thoracic cavity.
C) expands the rib cage.
D) flattens the floor of the thoracic cavity.
E) stimulates the phrenic nerve.

Question

Quizplus · Accepted Answer

During expiration, the diaphragm and external intercostals relax, decreasing the volume of the thoracic cavity and increasing the pressure, which pushes air out of the lungs.

During Expiration, Relaxation of the Diaphragm and External Intercostals