38 THORAX 



of the mediastinum. Thus, it is deeply hollowed out in 

 adaptation to the pericardium upon which it fits. The 

 pericardial concavity occupies the greater part of the 

 mediastinal surface, and, owing to the greater projection 

 of the heart to the left side, it is much more extensive in 

 the left lung than in the right lung. 



Groove for arch of aorta 



Left pulmonary artery 



Upper left 



pulmonary 'vein 



Left bronchus 



Lower left 

 pulmonary vein 



Pulmonary 

 ligament 



Groove for 

 oesophagus 



Groove for left subclavian artery 

 Groove for left innominate vein 



roove for first ril> 



Groove for tissue in 

 mediastinum, 



thymus, etc. 



Groove for conus 

 arteriosus 



Depression for 

 left ventricle 



- Cardiac notch 



FIG. 1 6. Medial of a Left Lung hardened in situ. 



At the upper and posterior part of the pericardial area is 

 the hilus of the lung. This is a wedge-shaped depressed area 

 through which the bronchus and the pulmonary artery enter 

 and the pulmonary veins and lymphatics leave the lung. It 

 is surrounded by the pleura which is reflected from its margin 

 on to the root of the lung, and the layer of reflected pleura 

 round the hilus is continuous, below, with the pulmonary 

 ligament. The portion of the pericardial area anterior to the 

 upper part of the hilus of the left lung corresponds with the 



