Exhalation Begins When

Question

Exhalation begins when
A)Inspiratory muscles relax
B)Diaphragm contracts
C)Blood circulation is the lowest
D)Both Inspiratory muscles relax and Diaphragm contracts
E)All of these choices

Accepted Answer

Exhalation begins when the inspiratory muscles, including the diaphragm, relax. This relaxation increases the pressure in the thoracic cavity, pushing air out of the lungs.