[Lung emphysema].

1. Elastic recoil, size of the perfused surface for gas exchange and flow resistance of the small airways influence the symptomatology and lung function of pulmonary emphysema independently of each other. 2. The loss of elastic force and surface for gas exchange are predominant in panlobular emphysema. Ventilation-perfusion disturbances due to increased airway resistance during inspiration and expiration predominate in chronic obstructive bronchitis with centrilobular emphysema. 3. In the presence of identical values for vital capacity and FEV1.0, arterial blood gas studies during rest and exercise provide the most reliable information on gas exchange surface and ventilation-perfusion disorders.