Which condition involves hyperinflation of air sacs with destruction of alveolar walls?

• A. Asthma
• B. Influenza
• C. Emphysema
• D. Olfaction

Answer: (C)

Hyperinflation of the air sacs with destruction of alveolar walls describes emphysema, a form of COPD. In emphysema, enzymes from inflammatory cells break down elastic tissue in the alveolar walls, causing the air sacs to enlarge and the surface area for gas exchange to shrink. This loss of elastic recoil makes exhalation less effective, so air gets trapped and the lungs become chronically overinflated. That combination—alveolar wall destruction plus air trapping leading to hyperinflation—fits emphysema best. By contrast, asthma involves reversible airway narrowing without this widespread alveolar destruction, influenza is an acute infection, and olfaction is a sense related to the nose, not lung structure.