A Stab Wound to the Chest Causes the Lung to Collapse

Question

A stab wound to the chest causes the lung to collapse because
A) of a sudden increase in surface tension.
B) intrapulmonic pressure becomes less than atmospheric pressure.
C) intrapulmonic pressure becomes higher than intrapleural pressure.
D) intrapleural pressure becomes greater than intrapulmonic pressure.

Accepted Answer

Intrapleural pressure becomes greater than intrapulmonic pressure, causing the lung to collapse. Normally, the intrapleural pressure is less than the intrapulmonic pressure, helping to keep the lungs expanded. A stab wound allows air to enter the pleural space, increasing the intrapleural pressure above that of the intrapulmonic pressure, leading to a collapsed lung.