What occurs in a closed pneumothorax?

• A. Air enters the pleural space through the chest wall
• B. Air enters the pleural space through an opening in the pleura
• C. Air is trapped within the lung tissue
• D. Fluid accumulates in the pleural cavity

Answer: (B)

In a closed pneumothorax, air enters the pleural space due to the rupture or damage to the lung itself rather than through the chest wall or an external opening in the pleura. This typically occurs from factors such as the rupture of alveoli or other lung structures, which can happen spontaneously or as a result of injury. The key distinction is that the airway is intact, meaning the air comes from within the lung rather than being introduced through an external breach.

The notion that air enters the pleural space through an opening in the pleura is indicative of a different type of pneumothorax, such as an open pneumothorax, where air can flow in freely from the external environment due to a defect in the chest wall. Thus, understanding that a closed pneumothorax involves internal lung damage is crucial for recognizing its pathophysiological implications. This concept highlights the significance of the mechanisms of injury and the resulting complications associated with various types of pneumothoraxes.