THORACIC CAVITY 



95 



aortic orifice, mitral orifice, tricuspid orifice. The centre of the 

 pulmonary orifice is posterior to the third left -costal cartilage 

 at the margin of the sternum. The aortic orifice lies 

 posterior to the left half of the sternum opposite the third inter- 



Right common carotid artery 

 Orifice of right internal jugular vein I 



Right subclavian artery 1 

 Right subclavian vei 



Innominate artery 



Right superior inter- 

 costal vein 



Vena azygos - 



Eparterial branch of 

 right bronchus 



Stem of right bronchus 

 Right vagus nerve 



Right intercostal vein 



Right aortic intercosta 



artery 



Right great splanchnic 

 nerve 



Right sympathetic --- 

 trunk 



Inferio 



Left common carotid artery 

 End of left internal jugular vein 

 i Left subclavian artery 

 I Left subclavian vein 



Trachea 



Termination of 



aortic arch 



"" Left bronchus 

 Left vagus nerve 



Descending thoracic aorta 

 -- CE&ophageal plexus 



FIG. 47. Dissection of the Posterior Mediastinum and the posterior part 

 of the Superior Mediastinum from the anterior aspect. 



costal spaces. The mitral orifice is posterior to the left border 

 of the sternum at the level of the fourth left costal cartilage ; 

 and the centre of the tricuspid orifice is posterior to the middle 

 of the sternum at the level of the fourth intercostal spaces. 



The Thoracic Portion of the Trachea. The thoracic 

 portion of the trachea, like the cervical portion, is a wide 



