1. Catarrhal Inflammation

This is one of the most common diseases of the air-passages. It may be either acute or chronic, and in one or other of these forms often attacks only single portions of the whole bronchial apparatus. In the acute form, however, it not unfrequently extends over the whole bronchial tract, and in the chronic form also is sometimes as widely diffused, but in this case the inflammatory action is more intense at some points than at others.

We distinguish, according to their positions, catarrhs of the larynx, trachea, and bronchi; or laryngitis, tracheitis, and bronchitis eatar-rhosa.

A. Acute Catarrhal Inflammation Of The Respiratory Organs

This presents the same anatomical appearances in whatever part of the bronchial system it occurs; there are various degrees of redness, relaxation, and swelling of the tissue, which, according to the intensity and stage of the affection, secretes a diminished or increased amount of muco-serous, frothy fluid (sputum crudum), or thick whitish or yellowish puriform mucus (sputum coctum), or, finally, of true purulent matter (the transition to superficial suppuration). The swelling of the mucous membrane and the submucous tissue, which assume the form of watery infiltration, from the areolar tissue being accumulated at individual spots, is important and worthy of great attention, on account of the facility with which it interferes with the calibre of the tubes. This swelling of the mucous membrane is most dangerous when it affects the epiglottis, the folds limiting the glottis, the covering of the vocal chords, and the portion lining the ventricles: the danger is less, but still very great, when it attacks the smaller bronchial tubes.

Acute bronchial catarrh, when widely diffused, is an important, and in children a perilous disease, not only in consequence of the contraction and perfect impermeability of the bronchial tubes caused by the swelling of the mucous membrane and the accumulation of its secretion, but from its occasionally, and especially in children, extending to the air-cells, forming catarrhal pneumonia.