If the thoracic wall is punctured, air leaking in will cause the lung to collapse. Thus, in the normal, intact thoracic cavity,

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Quizplus · Accepted Answer

In the normal, intact thoracic cavity, a slight suction or negative pressure keeps the lungs inflated. This negative pressure is created by the movements of the diaphragm and the intercostal muscles during breathing. When the lungs expand, they create a negative pressure that causes air to flow into the lungs. When the muscles relax, the lungs recoil and air is forced out of the lungs. This negative pressure is necessary to maintain the shape and function of the lungs. If the thoracic wall is punctured, air can leak into the pleural cavity and disrupt the negative pressure. This can cause the lung to collapse because the pressure inside the lung becomes equal to the pressure outside the lung.

If the Thoracic Wall Is Punctured, Air Leaking in Will