Various forms are distinguishable. This is an inflammation of the larger and middle-sized tubes, but not involving to any considerable degree the finer ones. In the slighter forms of bronchitis the larger bronchi and the trachea are mainly affected. In fact, it frequently happens that along with a slight laryngitis there is a tracheitis and a bronchitis of the larger stems. In the more definite cases of bronchial catarrh it is the middle-sized tubes that are chiefly involved. As already noted, capillary bronchitis associates itself with inflammation of the parenchyma of the lung, and will be considered in that section.