5 



THORAX 



At the upper and posterior part of the pericardial area is 

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

 through which the bronchus and the pulmonary artery, nerves, 

 veins, and lymph vessels enter or leave the lung. It is sur- 

 rounded by the pleura which is reflected from its margin on to 

 the root of the lung, and the layer of reflected pleura round 



Internal mammary vessels 



^T^ 



Anterior papillary 

 muscle 



Conus arteriosus 

 cavity 



Post cusp of valve 

 of pulmonary artery 

 Left coronary artery. 



Left phrenic nerve 

 Auricle of left atrium 



Left pulmonary 

 artery 



Left bronchus 



Lymph gland 



Left vagus nerve 



Descending aorta 



Accessory 

 hemiazygos vein 



Pectoralis major 

 Fourth costal 

 cartilage 



Auricle of right 

 atrium 



Pericardial cavity 

 Right coronary arte 



Ascending aorta 

 Superior vena cava 



Right phrenic nerv 



Right pulmonary 

 artery 



Right bronchus 



Right vagus nerve 

 Lymph glands 

 CEsophagus 

 Vena azygos 



Thoracic duct 

 Intervertebral carti 

 age between 5th an 

 6th thoracic vertebr 

 Sixth rib 



Fifth rib 



FIG. 20. Transverse section through the Thorax of a -young Male Adult 

 along the plane C-C, Fig. 15. 



the hilum is continuous, below, with the pulmonary ligament 

 (Figs. 1 8, 19). 



The portion of the pericardial area anterior to the upper 

 part of the hilum of the left lung corresponds with the 

 position of the conus arteriosus and the stem of the pulmonary 

 artery (Fig. 18); and the same portion of the pericardial 

 area on the right side corresponds with the position of the 

 lower part of the superior vena cava posteriorly, and with 



