What is the medical term for the deflation of alveoli in the lungs?

Atelectasis refers specifically to the partial or complete collapse of the alveoli in the lungs, leading to a reduction in the surface area available for gas exchange. This condition can occur for various reasons, such as obstruction of the airway, lack of surfactant, or pressure from outside the lungs. When the alveoli are unable to inflate or remain fully expanded, this can result in respiratory distress and decreased oxygenation of the blood.

The other terms listed do not pertain to the deflation of alveoli: pleural effusion involves the accumulation of fluid in the pleural space between the lungs and the chest wall, excision refers to the surgical removal of tissue, and ablation involves the destruction of tissue, often through various means such as heat or cold. Each of these does not directly describe the process of alveolar collapse as atelectasis does.