Collapse of alveoli resulting in reduced gas exchange is called?

• A. Atelectasis
• B. Wheeze
• C. Stridor
• D. Tachypnea

Answer: (A)

Atelectasis is the collapse or incomplete expansion of alveoli, which reduces the surface area available for gas exchange. When alveoli collapse, less oxygen can diffuse into the blood and less carbon dioxide can be released, leading to hypoxemia and potential respiratory distress. This condition can arise from airway obstruction (resorption atelectasis), external compression (compression atelectasis), or surfactant deficiency that makes alveoli less stable (adhesive atelectasis). The other terms describe different problems: wheeze is a musical sound from narrowed airways, stridor is a harsh sound from upper airway obstruction, and tachypnea is rapid breathing, a symptom rather than a specific alveolar collapse.