Benzoic acid is also excreted by the bronchi and tends to disinfect and stimulate the bronchial mucous membrane.
The majority of birds possess a pair of internal tympaniform membranes forming the inner or median walls of the bronchi, which are there furnished with semi-rings only.
The drug is excreted partly by the bronchi - which it tends to disinfect - and partly in the urine, which it causes to smell of violets.
The secretion of mucus by the bronchi and trachea is greatly reduced and their muscular tissue is paralysed - a fact of which much use is made in practical medicine.
The structural changes occurring in the bronchi in catarrhal bronchitis have also been ascertained, and, as in the case of pneumonia, have been shown to be frequently excited by the presence of a microphyte.