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 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.
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 places mentioned are all suitable for persons suffering from chronic bronchitis, who should avoid any irritation of the larynx, trachea or bronchi by air which is too dry or which is liable to great changes of temperature.
In the event of the host escaping being killed and eaten it is believed that some of these larvae wander about or ultimately make their way to the exterior, possibly through the bronchi; nevertheless it seems to be certain that they can only reach sexual maturity in the nasal passages of some carnivorous animal, and the chance of attaining this environment is afforded when the viscera of the host are devoured by some flesh-eating mammal.
The motor nerves of the arteries, of the bladder and rectal sphincters, and also of the bronchi, are paralysed by atropine, but the nervous arrangements of those organs are highly complex and until they are further unravelled by physiologists, pharmacology will be unable to give much information which might be of great value in the employment of atropine.