THE MICROANATOMY OF THE ALVEOLAR DUCT OF THE HUMAN LUNG IMAGED BY CONFOCAL MICROSCOPY AND VISUALIZED WITH COMPUTER-BASED 3D RECONSTRUCTION

The most widely accepted model of human lung alveolar duct systems is that they are constructed from central helical fibres between the turn s of which lie alveolar openings. Experimental difficulties of handlin g and sectioning lung tissue have made it difficult to confirm this. C onfocal laser scanning microscopy (CLSM) was therefore used to generat e optical serial sections of the lung that were reconstructed in three dimensions and displayed using volume rendering techniques. From imag es of the reconstructions, a new structure is proposed in which alveol ar ducts consist of collections of connected oval, twisted loop struct ures with eccentric openings.