As the thoracic cavity begins to expand, the intrathoracic pressure:
A) does not change.
B) is greater than atmospheric pressure.
C) is the same as atmospheric pressure.
D) is less than atmospheric pressure.

Question

Quizplus · Accepted Answer

As the thoracic cavity expands, the volume inside the cavity increases, which results in a decrease in pressure inside the cavity. Therefore, the intrathoracic pressure is less than atmospheric pressure.

As the Thoracic Cavity Begins to Expand, the Intrathoracic Pressure