1834 



HUMAN ANATOMY. 



geal nerve : posterior crico-arytenoid paralysis with stridor and inspiratory dyspnoea 

 (page 1273). (/■) The sympathetic : various disturbances of vision ; irregular pupils. 



4. Compression of the thoracic duct. Emaciation ; chylo-thorax ; chylous 

 ascites ; mediastinal effusion of chyle. 



5. Compression of the air-passages, (a) The trachea : stridor ; dyspnoea. 

 (d) The bronchi : feeble breath-sounds ; dyspnoea ; recession of the suprasternal 

 and supraclavicular fossae and base of chest ; cough. (c) The lungs and pleura : 

 dyspnoea ; collapse of the lungs ; pleural effusion. 



6. Compression of the heart and pericardium. Displacement of the heart ; peri- 

 cardial effusion ; irregular heart acuon. 



7. Compression of the oesophagus. Dysphagia. 



8. Outward pressure upon the walls of the mediastinal space. Widening of inter- 

 costal spaces ; bulging of the sternum ; increase of the circumference of the chest on 



one side ; weakness or 

 Fig 1 55^. absence of vocal fremi- 



tus ; increased area of 

 transmission of heart- 

 sounds. . 



Of course, all of 

 these symptoms are not 

 present in any given case 

 of mediastinal growth, 

 but some of them are 

 sure to be and can be 

 more readily understood 

 if referred to their ana- 

 tomical causes. 



The phenomena ref- 

 erable to the separate 

 subdivisions of the me- 

 diastinum can be classi- 

 fied only in a very gen- 

 eral way. It may be 

 said, however, that: (i) 

 The anterior mediasti- 

 num is the most fre- 

 quent seat of abscess ; 

 that its growths usually 

 begin in the thymus ; 

 and that the chief symp- 

 toms are apt to be those 

 of pressure upon the su- 

 perior vena cava, inva- 

 sion of the suprasternal 

 fossa, involvement of the 

 cervical glands, bulging 

 or erosion of the ster- 

 num, and dyspnoea. (2) 

 Growths of the poste- 

 rior and middle mediastinum are apt to originate in the lymph-nodes, and the chief 

 symptoms a'-e those of pressure upon the pneumogastric, recurrent laryngeal or sym- 

 pathetic nerves, the greater azygos vein, the oesophagus, and the air-passages. The 

 urgent dyspnoea and troublesome cough are out of all proportion to the physical 

 signs (Osier). 



THE TRACHEA. 



The trachea or windpipe (Fig. 1558) is a tube, composed of cartilage and mem- 

 brane, extending from the cricoid cartilage to a point opposite the disk below the 

 fourth thoracic vertebra, corresponding to the level of the junction of the first and 



Trachea and bronchial tree, anterior aspect. A", /,, right and left bronchus; 

 A, left apical bronchus dividing into ventral (a) and dorsal (a') branches; B, 

 continuation of main bronchus; b, d', ventral and dorsal branches; c, cardiac 

 bronchus. 



