What is pneumothorax primarily defined as?

• A. Fluid in the alveoli
• B. Collapsed lung due to air in the pleural cavity
• C. Pneumonia caused by bacterial infection
• D. Swelling of the lung tissue

Answer: (B)

Pneumothorax is primarily defined as the presence of air in the pleural cavity, which leads to the collapse of the lung on the affected side. This condition occurs when the pleural space, the thin fluid-filled space between the two layers of pleura that surround the lungs, becomes filled with air. The air can come from various sources, such as a ruptured bleb, injury, or can occur spontaneously. This accumulation of air increases pressure in the pleural cavity and disrupts the normal negative pressure that is necessary for lung expansion during breathing, ultimately causing the lung to collapse partially or completely.

Understanding the mechanisms behind a pneumothorax is crucial for identifying its implications in respiratory function and determining appropriate interventions, such as chest tube placement or surgical options. The condition can lead to significant respiratory distress, and recognizing its definition aids healthcare professionals in swiftly diagnosing and managing the issue.