Which of the following does NOT happen when the diaphragm contracts
A)The volume of the thoracic cavity increases.
B)Lung volume increases as the lungs are forced to expand.
C)Intra-alveolar pressure increases.
D)Intrathoracic pressure decreases.

Question

Quizplus · Accepted Answer

When the diaphragm contracts, it pulls downward and increases the volume of the thoracic cavity. This increase in volume causes a decrease in intrathoracic pressure, which allows air to flow into the lungs and increase lung volume. However, intra-alveolar pressure does not increase during diaphragm contraction; it actually decreases as air flows into the lungs.

Which of the Following Does NOT Happen When the Diaphragm