How does emphysema affect gas exchange in the lungs?

Emphysema is a form of chronic obstructive pulmonary disease (COPD) characterized by the destruction of the alveoli, the tiny air sacs in the lungs where gas exchange occurs. In healthy lungs, these alveoli provide a large surface area for the diffusion of oxygen and carbon dioxide between the air and blood. However, in emphysema, the walls of the alveoli are damaged and can collapse, leading to the formation of larger, less efficient air spaces. This reduction in the number of functional alveoli drastically decreases the overall surface area available for gas exchange.

As a result, the ability to exchange oxygen and carbon dioxide becomes inefficient, causing individuals with emphysema to experience difficulty in breathing and inadequate oxygenation of the blood. This is why the correct answer is that emphysema decreases surface area, making gas exchange inefficient. Understanding this mechanism is crucial for managing patients with emphysema and recognizing the impact of the disease on respiratory function.