THORAX 



branches'; (2) the ligamentum arteriosum, which connects the 

 commencement of the left pulmonary artery with the arch ; 

 (3) the superficial part of the cardiac plexus, immediately to 

 the right of the ligamentum arteriosum ; (4) the left recurrent 



ternal 



Phrenic nerve 

 Aortic arch 



Vagus nerve 



Recurrent 

 nerve 



Left superior 

 intercostal vein 



(Esophagus 

 Thoracic duct 



Sympathetic 

 trunk 



FIG. 57. Transverse section through the Superior Mediastinum 

 at the level of the fourth thoracic vertebra. 



nerve, on the left side of the ligament ; and (5) still further 

 to the left, the left bronchus passes beneath the arch on its 

 way to the hilum of the left lung. To the right of the arch 

 and somewhat behind it are the trachea, the oesophagus, the 

 left recurrent nerve, and the thoracic duct. The nerve lies 

 in the angle between the oesophagus and the trachea, and 

 the thoracic duct is posterior to, and to the left of, the 



