question_answer 33)

    Cigarette, smoking causes emphysema. Give reason.

Answer:

                  Emphysema is a chronic disorder of respiratory system, where inflation or abnormal distension of alveolar wall occurs. Cigarette smoking and the inhalation of other smoke or toxic substances over a period of time causes the damaging of septa between the alveoli, and of its elastic tissue is replaced by the connective tissue in lungs. Hence, the respiratory surface decreases, thus causing the emphysema. It causes shortness of breath, production of sputum, chronic bronchitis, etc.