[Mechanisms of bronchial self-cleaning. Surface studies on the bronchial mucosa, bronchial basement membrane and subepithelial connective tissue. A scanning electronmicroscopic study].

Bronchial mucosa and bronchial basement membranes of man and of healthy slaughter animals were examined with the scanning electron microscope. The surface relief of the normal human bronchus mucosa is composed of a system of bulge-like prominences and valleys. There are parallel recesses and narrow valleys which run parallel to the longitudinal axis of the bronchus. Man and pig have the same kind of surface relief in bronchus. A fundamental different type of surface area relief is exhibited by the cow and the sheep. The bronchial basement membrane is a homogeneous plate with dune-like prominences and trough-shaped depressions. Often one can see perforations of variable size. The structures of the basement membranes have a great variability and no species-specifity. There are the same types of dysplasias in the bronchus mucosa in man and in animals. The differences are based upon in the wideness of the expansion and in the grade of the dysplasias in man.