Atelectasis is defined as?

Atelectasis is defined as?

• A. Collapsed lung
• B. Fluid in the lungs
• C. Lung cancer
• D. Pneumonia

Answer: (A)

Atelectasis means part or all of the lung has deflated and the air sacs (alveoli) have collapsed, so that that region is not filled with air and cannot participate in gas exchange. It happens when airways are blocked (for example by mucus plugs), when something presses on the lung (fluid or a mass), or when surfactant is lacking. That collapsed area shows up as decreased breath sounds and can appear as a dense region on imaging. The other options describe fluid in the lungs, a lung tumor, or infection with alveolar filling, none of which are a collapse of the alveoli.

Atelectasis means part or all of the lung has deflated and the air sacs (alveoli) have collapsed, so that that region is not filled with air and cannot participate in gas exchange. It happens when airways are blocked (for example by mucus plugs), when something presses on the lung (fluid or a mass), or when surfactant is lacking. That collapsed area shows up as decreased breath sounds and can appear as a dense region on imaging. The other options describe fluid in the lungs, a lung tumor, or infection with alveolar filling, none of which are a collapse of the alveoli.