Question

Cigarette smoking causes emphysema. Give reason.

Answer 1

Emphysema :

Emphysema is a chronic disorder which occurs due to cigarette smoking for a prolonged period.

Reason :

Excessive cigarette smoking damages the walls of the alveoli due to increased exposure of tobacco. This leads to loss of elasticity of walls of the alveoli. The inner walls of the air sacs get ruptured which creates larger air spaces instead of numerous small ones. As a result, the effective surface area for the exchange of gases is reduced.

During exhalation, malfunctional alveoli do not permit accurate expulsion of old air. Hence, the alveolar sacs remain considerably filled with air even after expiration which creates lesser space for fresh, oxygen-rich air.