atelectasis

(noun)

The collapse of a part of or the whole lung caused by inner factors, rather than a pneumothorax.

Examples of atelectasis in the following topics:

Factors Affecting Pulmonary Ventilation: Surface Tension of Alveolar Fluid
- Other diseases may cause atelectasis, such as COPD, or any sort of lung trauma and inflammation that involves extensive damage to the pleural cavity or the lung parenchyma.