rnor 



PEEICAEDIUM. 



881 



mediastinum, and it is attached, above and below, by the superior and inferior 

 sterno-pericardial ligaments, to the sternum. In the greater part of its extent 

 it is separated from the anterior wall of the thorax by the anterior margins of the 

 lungs and pleural sacs, but it is in direct relation with the left half of the lower 

 portion of the body of the sternum and, in many cases, with the medial ends of the 

 cartilages of the fourth, fifth, and sixth ribs of the left side and the left transversus 

 thoracis muscle. Its posterior surface forms the anterior boundary of the posterior 



Right common carotid 



Inferior thyrcoid veins 



Left common carotid artery 



Right internal jugular vein.. 

 Right subclavian artery 

 Right subclavian vein j 



Left internal mammary vein 



Right internal mammary vein--- 



.it edge of fibrous pericardium 



Superior vena cava ** 



it edge of serous pericardium 1"^ 



Aorta--- 



Division of pulmonary artery 

 Right pulmonary artery- 

 Superior vena cava- 

 Ipper right pulmonary vein .- 



nver right pulmonary veil 



Cut edges of serous 



pericardium" " " 



Inferior vena cava , . 



Left internal jugular vein 



-Thoracic duct 



-Left subclavian artery 



-Left subclavian vein 



Left phrenic nerve 

 Left vagus nerve 



Left superior intercostal vein 



Left recurrent nerve 

 Ligamentum arteriosum 



Left pulmonary artery 



Arrow in great transverse sinus 

 of pericardium 



Left bronchus 



Upper left pulmonary vein 



--- Lower left pulmonary vein 



. Fibrous pericardium 

 Serous pericardium 



} . 756. POSTERIOR WALL OF THE PERICARDIUM AFTER THE REMOVAL OF THE HEART. 

 Showing the relation of the serous pericardium to the great vessels. 



mediastinum ; it is in relation with the oesophagus and the descending aorta, 

 both of which it separates from the back of the left atrium. Each lateral aspect 

 is in close contact with the mediastinal portion of the parietal pleura, the phrenic 

 nerve and its accompanying vessels intervening. The inner surface of the fibrous 

 sac is lined by the serous pericardium, which is closely attached to it. 



The serous pericardium is a closed sac containing a little fluid (liquor peri- 

 cardii). It is surrounded by the fibrous pericardium and in vagina ted by the heart. 

 It is, therefore, separable into two portions the parietal, which lines the inner sur- 

 face of the fibrous sac, and the visceral, which ensheaths, or partially ensheaths, the 

 heart and the great vessels ; but the two portions are, of course, continuous with 

 one another where the serous layer is reflected on to the great vessels as they pierce 

 the fibrous layer. The majority of the great vessels receive only partial coverings 

 from the visceral layer : thus, the superior vena cava is covered anteriorly and on 



57 



