CHAPTER V. 



DISEASES OF STRUCTURES ENCLOSED WITHIN THE 



MEDIASTINUM. 



The mediastinum is a space enclosed in the median plane of the 

 thorax by the approach of the two opposite layers of pleura. Needless 

 to say, at those points where the layers are in apposition, the space is 

 theoretical only. It extends from the suprasternal region to the dorsal 

 subvertebral region, and encloses all the vessels which pass from or to 

 the base of the heart, the trachea, the oesophagus, the pneumo-gastric, 

 diaiAragmatic and cardiac nerves, etc., as well as the pericardial sac and 

 the heart. The organs most frequently affected are the lymphatic glands 

 lodged in the thickness of the mediastinum, the glands placed at the 

 entrance to the chest, the bronchial glands, and the glands situated in the 

 posterior mediastinum. 



Inflammation of the mediastinum may coincide with inflammation of 

 the mediastinal layers of the pleura ; but this can only he detected on 

 post-mortem examination. The lesions which can be recognised during 

 life are simple inflammation of glands, resulting from pulmonary or 

 pleural diseases, tuberculous inflammation of glands, and the presence of 

 cancerous tumours of the mediastinum and hypertrophy of glands due 

 to lymphadenitis. 



Simple inflammation of the lymphatic glands is secondary and 

 consecutive to broncho-pneumonia, verminous bronchitis, infectious 

 bronchitis, etc. 



It i^roduces reflex irritation by compressing the pneumo-gastric and 

 laryngeal nerves, and is indicated by loud, spasmodic coughing. 



Treatment consists in administering iodide and bromide of potassium, 

 terpine, in doses of 1 drachm per day for adults, essence of turpentine 

 and tar water. 



Tuberculous inflammation of glands, inseparable from pulmonary 

 tul)erculosis, has very special characteristics peculiar to tuberculosis. 



Inflammation due to lymphadenitis is also very easy to diagnose 

 as a rule, in consequence of the symmetrical enlargement of lymphatic 

 glands elsewhere. 



