1190 



THE ORGANS OF VOICE AND RESPIRATION 



Applied Anatomy. Primary tumors of the mediastinum are usually lymphomata or lympho- 

 sarcomata arising from the thymusor from the bronchial or posterior mediastinal lymph nodes; 

 sarcomata, dermoid cysts, and embryomata, occur more rarely. These tumors give rise to pain, 

 deformity of the thorax, and symptoms of pressure on the various nerves, bloodvessels, air 

 passages, lymphatics, and on the oesophagus, as these various structures pass through the thorax. 

 They may produce physical signs very much like those of an aortic aneurism, so that diagnosis 

 between the two is often difficult. The prognosis is bad, life usually ending within a few months 

 or a year of the onset of the symptoms. 



Inflammation of the mediastinum due to wounds, or to the spread of inflammation from ad- 

 jacent parts (e. g., the oesophagus, the pericardium), is sometimes acute, leading to abscess 

 formation. A more chronic form associated with adhesions and inflammation of the pericar- 

 dium the so-called chronic adhesive mediastinopericarditis gives rise to obscure symptoms 

 suggesting gradual heart failure, and leads to death slowly but surely. 



THE LUNGS (PULMONES) (Figs. 903, 904). 



The lungs are the essential organs of respiration; they are two in number, 

 placed one on each side of the thorax, separated from each other by the heart and 

 other contents of the mediastinum. A healthy lung hangs free within the pleural 

 cavity. It is suspended by the root and by the ligamentum pulmonale. In many 



GROOVE FOR 

 INNOMINATE VEIN 



LINE OF REFLECTION 

 OF PULMONARY 

 /PLEURA ON TO 

 ROOT OF LUNG 



LIGAMENTUM 

 LATUM PULMONIS 



FIG. 903. The right lung. The inner or mediastinal surface, with the hilum laid bare by the removal of the 

 structures forming the root of the lung. (Toldt.) 



cases examined the lung does not hang free, but, as a result of former pleurisy, 

 an area of the pulmonary pleura is adherent to the parietal pleura. Each lung 

 is conical in shape, and presents for examination an apex, a base, three borders, 

 and three surfaces. 



The apex (apex pulmonis) is rounded, and extends into the root of the neck 

 about an inch to two inches above the level of the anterior end of the first rib. 

 A furrow produced by the subclavian artery as it curves outward in front of the 

 pleura runs upward and outward immediately below the apex. The brachial 

 plexus is in close proximity to this portion of the lung. 



