Abstract
Adult laying hens were subjected to a study on analysis of the mechanism responsible for genesis of a spontaneous deformation of the expiratory-oxygen curve. First, an induction of the deformation was examined by infusing a pasty barium suspension into the unilateral primary bronchus. This maneuver caused the expiratory-oxygen curve to deform. The pattern of differential pressure changes between the bilateral extrapulmonary primary bronchi differed depending on which part of the primary bronchus was obstructed with the barium suspension. It was then examined which pattern of the differential pressure changes could be recorded at the time of a spontaneous deformation, so that the obstruction might be detected. Secondly, it was determined whether the spontaneous airway obstruction so detected was partial or complete, by using a technique in which nitrogen-gas was flushed into the extrapulmonary primary bronchi. As a result, it was concluded that the spontaneous deformation of the expiratory-oxygen curve was induced by the airway obstruction in the cranial lumen of the extrapulmonary primary bronchus on either side, and that this obstruction was not complete but partial.
