480 THE RESPIRATORY SYSTEM. 



indrical dilatation of a number of the medium-sized bronchi often 

 occurs. 



In the persistent broncho-pneumonia of children such dilatations may 

 reach a still greater development. ' Chronic bronchitis may lead to cylin- 

 drical or sacculated dilatations, sometimes of great size. 



Occlusion of some of the bronchi, consolidation of portions of the 

 lung, and extensive pleuritic adhesions may also lead to bronchiectasia 

 (Fig. 264). 



The walls of bronchiectatic cavities may be lined with mucous mem- 

 brane, which, however, is apt to undergo various changes as the process 

 advances. Thus the subepithelial layer may be vascular and cellular and 

 thrown into folds, or it may be thin and dense. The epithelium is often 



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. .. ^.: * ' --' ^^ W^^6 .<*-- '/ 



;iv"ff?Pi' P| 



//'. f ; * 



, ,/ ..4* ^ . , aj? / */ff 



\*Ml . e/j, , M?3 



f-\* ' %tV\^~-^V^' 



- ''* \ ^ y X^^^^o;i 



^m\ ./m 



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FIG. 2&5. PRIMARY ADENOMA OF THE BRONCHI 



irregular, sometimes irregularly thickened, sometimes thin, or it may be 

 largely absent. The glands, muscle, and cartilages of the walls of the 

 bronchi may disappear through atrophy. The presence of certain forms 

 of bacteria in the exudate in brouchiectasia may lead to offensive putre- 

 factive process and even to gangrene. 



In acute and chronic phthisis the tuberculous inflammation of the 

 walls of the bronchi often gives rise to sacculated dilatations, which 

 expand with time and become still larger by the destruction of the adja- 

 cent lung tissue tuberculous bronchiectasise. 



1 For a study of bronchiectasia in children see Lapin, Arch. f. Kinderheilkunde, Bd. 

 xxx vii., 1903, p. 406. 



