What happens to the alveoli in emphysema?

In emphysema, the primary pathological change involves the destruction of the walls of the alveoli, the tiny air sacs in the lungs where gas exchange occurs. This destruction leads to an enlargement of the air spaces, meaning the alveoli distend and lose their natural elasticity. As a result, the surface area available for gas exchange is significantly reduced, making the alveoli much less functional.

In a healthy lung, the alveoli are small and numerous, providing a large surface area for oxygen to enter the blood and carbon dioxide to be expelled. However, in emphysema, the walls between adjacent alveoli break down, leading to larger, fewer alveolar spaces. This process creates a situation where the alveoli cannot effectively exchange gases due to the impaired elastic recoil, leading to issues like shortness of breath and reduced oxygenation during physical activity.

The other options do not accurately describe the changes in the alveoli related to emphysema. Inflammation is more characteristic of conditions like chronic bronchitis, while complete collapse and fluid filling are not typical processes seen in emphysema itself.