શ્વસનતંત્રના રોગનું નામ આપો. જેમાં વાયુકોષ્ઠની સપાટીનો વિસ્તાર જે વાતવિનિમય સાથે સંકળાયેલ છે, તે વાયુકોષ્ઠની દીવાલો તેમાં ભંગાણને કારણે ખૂબ જ ઘટી જાય છે.

(d) : Emphysema is an inflation or abnormal distension of the bronchioles or alveolar sacs of the lungs. Many of the septa between the alveoli are destroyed and much of the elastic tissue of the lungs is replaced by connective tissue. As the alveolar septa collapse, the surface area for gas exchange is greatly reduced. There is loss of elasticity in the walls of bronchioles or alveolar sacs. As a result the alveolar sacs remain filled with air even after expiration. The exhalation becomes more difficult. The lungs remain inflated. Major causes of emphysema are cigarette smoking and the inhalation of smoke or other toxic substances over a period of time.