Variations in bronchial movement.

Studies of bronchial movement in bronchi and bronchioles following routine bronchography are presented with the aid of a magnification technique. Wide variations of calibre were demonstrated on full inspiration and extreme expiration, most marked in the smaller bronchi. During coughing, maximal differences of width were noted in the larger airways, with little change in the smallest bronchi. In order to assess the changes, reference is made to previous records when, using a three-channel writing oscillograph, bronchial measurements, intra-oesophageal pressures and lung volumes were estimated. Critical examination of the borders of the bronchial walls revealed that they were never straight nor truly parallel. They had smooth, undulating outlines, which were seen to alter on serial films. Irregularities in the airways without disease can be considerable, but when destructive changes are present, gross deformities may become apparent. With a full inspiratory effort, bronchial walls may be completely extended and appear normal, but on radiographs taken on expiration weakness of the bronchial wall may be revealed which otherwise would be missed. The inclusion of routine expiratory films on all bronchographic examinations is recommended.