Microscopic and ultramicroscopic alterations of the respiratory mucous membrane in experimentally provoked bronchitis.

The noses of four experimental dogs were surgically obstructed, and thus their entire respiration was disturbed, and this affected the mucous membranes of the lower respiratory passages. Normal histological examinations and electronic microscopy found chronic irritation of the bronchial mucous membranes. It was possible histologically to follow the most subtile alterations on the membranes from the very beginning of the chronic bronchitis. The importance of nasal obstruction as a contributing factor of chronic bronchitis is stressed.