During inspiration, muscular contraction of the diaphragm causes air to move into the lung. What is the mechanism that allows air to enter the lungs?
A) There is a decrease in intra-alveolar pressure and shortening of the rib cage.
B) There is a decrease in the size of the thorax and alveolar expansion.
C) There is an increase in the size of the thorax and creation of negative pressure.
D) There is an increase in atmospheric pressure and intrapleural pressure.

Question

Quizplus · Accepted Answer

During inspiration, the diaphragm contracts and moves downward, increasing the size of the thoracic cavity. This creates a negative pressure relative to the atmosphere, causing air to flow into the lungs.

During Inspiration, Muscular Contraction of the Diaphragm Causes Air to Move