Morphology of the bronchial lining layer and its alteration in IRDS, ARDS and COLD

Both light and electronmicroscopic examinations of the collocation of surfactant secreted by the alveoli into the bronchi were performed on material obtained from biopsies and autopsies. In the sol phase and especially along the border between the sol and gel phases of the bronchial mucus layers regularly arranged, partially stretched and partially reticulated osmiophilic membranes could be demonstrated. Their detailed structure corresponds with the structure of the phospholipid membranes of the surfactant in the alveoli. The functional significance of this surfactant portion for bronchial clearance is discussed in relation to the changes in structure of these membranous bodies, and their collocation in the mucus layers in chronic bronchitis, ARDS and IRDS.