LAR SYSTEM). The trachea itself is lined by delicate mucous membrane, which is covered by epithelial cells provided with delicate vibratile processes or cilia. The trachea derives its blood from the inferior thyroid arteries. Its nerves arise from the pneumogastric trunks and recur rent branches, as well as from the sympathetic system. Foreign bodies falling into the trachea most frequently enter the right bronchus, be cause of the larger size of the latter and be cause of the more oblique position of the left bronchus.
Diseases and Injuries of the Trachea— The trachea is liable to inflammation and its products and frequently suffers from extension of disease from the larynx. Acute inflamma tion may occur as an idiopathic affection or a symptom of other disease, as smallpox, measles, typhus, tuberculosis, croup, etc. The symptoms are pain in the windpipe from the top of the sternum, expectoration of mucus, sometimes in regular rings and a peculiar brazen-like cough. Chronic inflammation usually accom panies follicular pharyngo-laryngitis, tubercu losis and syphilis, and may extend to the sub mucous tissues and the cartilaginous structures, resulting in ulceration, cicitrization and stricture. The treatment consists in rest, the application of warm poultices, the inhalation of steam im pregnated with balsamic or anodyne substances and the administration of antiphlogistic rem edies. Constriction of the trachea may he pro duced by aneurismal or other tumors pressing externally on the trachea; or the symptoms may be produced by pressure on the nervous trunk or the inferior laryngeal fibres. Foreign bodies occasionally pass through the larynx into the trachea and the accident is a formid able one, which not unfrequently proves fatal. The accident occurs most frequently among children and is caused by a sudden inhalation while holding something in the mouth. Occa
sionally, however, a foreign body may, during the act of swallowing and without an inhala• Lion, pass under the epiglottis and into the upper part of the larynx. Foreign bodies in the wind pipe may be arrested above the rima glottidis, between the vocal cords, in the cavity of the larynx or in the trachea. In such cases the patient is suddenly seized with convulsive cough and dyspncea. The speech is more or less af fected and the breathing is whistling or stridulous; but the diagnosis rests mainly on the sudden accession of the symptoms. When the presence of a foreign body is made out, it ought to be removed at once. When the body is loose in the trachea, a free opening lower down should be at once made and the open ing may be either longitudinal or transversely valvular. It is advisable in nearly all cases to open the trachea, as, by securing a free aper ture for respiration, spasm of the glottis is obviated and the foreign body may be removed through the artificial opening, or it may fall through the glottis into the mouth. Fracture of the trachea occurs from direct violence and in such cases the wounded part should be laid freely open, so as to secure the passage of air to the lungs. Union of the wound by suture is to be avoided, that by suppurative inflamma tion being preferable, the head and neck being retained in a suitable position. Foreign bodies in the trachea and all kinds of injury from external violence are serious affections, as dis ease of the lungs is apt to be induced.
The term trachea as applied in respect to invertebrates connotes a more or less compli cated arrangement of air-tubes and spiracles (q.v.), most fully developed in insects and con stituting the respiratory system. See INSECTS. For the general subject, see ANATOMY; LUNGS;