Cigarette smoking causes emphysema. Give reason.

(N/A) Emphysema is a chronic disorder in which alveolar walls are damaged. Cigarette smoke contains harmful chemicals that trigger inflammation and the release of enzymes (like elastase) that break down the elastic fibers in the alveolar walls. As a result,the alveolar walls are destroyed,reducing the total surface area available for gas exchange. This leads to decreased respiratory efficiency,causing symptoms such as shortness of breath,chronic coughing,and bronchitis.