THE ARCH OF THE AORTA 



400 



Behind are the left auricle of the heart, the right pulmonary artery, the right 

 bronchus, and the anterior right deep cardiac nervc;^. 



On the right side it is in contact, below with the right auricle, and aV)Ove with 

 the su})eritn- vena cava. 



On the left side are the pulmonary artery and the branches of the right super- 

 ficial cardiac nerves. 



The Transverse Portion of the Arch of the Aorta 



The transverse portion of the arch of the aorta extends in a gentle curve 

 upwards, backwards, and to the left, from the level of the ujtper l;>order of the 

 second right costal cartilage to the left side of the body of the fourth thoracic 

 vertebra. Passing under the arch are the left bronchus, the right pulmonary 

 artery, and the left recurrent laryngeal nen'e. It measures about one inch au'l 

 four-rifths (4-0 cm.). 



Relations. — In front (fig. 323), it is slightly overlapped by the right pleura 



Fig. 3-23. — Scheme of the Relations of the Transverse Portion of the 

 Arch of the Aorta. (Walsham.) 



(ESOPHAGUS 



TRACHEA 

 Left carotid artery 

 Innominate artery 



RIGHT PLEURA 

 RIGHT LUNG 



THORACIC DUCT 



LEFT RECL'EREXT LARYSGEAL SERVE 



Left subclavian artery 



Lfft superior intenostal vein 



P'SELMOGASTRIC SERVE 



rARDHC BRASCHES OF SYMPATHETir 



CARDIAC BRAXCHES OF PXEUMOGA-^TRIC 



PHREXIC XER VE 



left lung 



Right pleura 



and lung, and to a greater extent by the left pleura and lung. It is crossed in the 

 following order from right to left, by the phrenic ner\-e, by the cardiac branches of 

 the pneumogastric nerve, the cardiac branches of the sympathetic nerve, by the 

 pneumogastric ners'e, and by the left superior intercostal vein as it passes up to the 

 left innominate vein. 



Behind it (fig. 323) are the trachea, the cesophagus. the thoracic duct, the 

 deep canliac plexus which is situated on the trachea just above its bifurcation, and 

 the left recurrent laryngeal nen'e. 



Above it (fig. 321) are the three chief branches for the head, neck, and upper 

 extremities, namely, the innominate, the left carotid and the left subclavian arte- 

 ries, and the left innominate vein. 



Below it — that is. in its concavity — are the bifurcation of the pulmonary 

 artery, the left bronchus, the left recurrent laryngeal nerve, the remains of the 

 ductus arteriosus, the superficial cardiac plexus, two or more bronchial lymphatic 

 glands (fig. 321), and the reflexion of the pericardium. 



