THORACIC CAVITY 



passing behind the fifth costal cartilage at the margin of the 

 sternum, or even an inch more laterally ; it then descends 

 to the lower border of the sixth cartilage, where it becomes 



(Esophagus 



Left subclavian artery \ 

 Left common carotid artery \ \ 

 Left superior intercostal vein 

 Left innominate vein 



Cut edge of 

 parietal pleura 



Pericardium 



Cut edge of 

 parietal pleura 



Aortic arch 



Pulmonary 

 artery 



Bronchus 



Lower pulmon- 

 ary vein 



(Esophagus 



Diaphragmatic 



pleura 



FIG. 8. Left Pleural Sac, of a subject hardened by formalin injection, 

 opened into by the removal of the costal pleura. The left lung also 

 has been removed so as to display the mediastinal pleura. The line 

 along which the pleura is reflected from the diaphragm on to the thoracic 

 wall is exhibited. 



continuous with the lower margin of the pleura, which passes 

 laterally and posteriorly along the lower border of the sixth 

 cartilage, across the medial end of the sixth space, and across 

 the seventh cartilage to the junction of the cartilage and 

 ii 2 a 



