AORTA 



141 



forming an arch, which, on reaching the vertebral column, 

 passes downwards as far as the body of the fourth lumbar 

 vertebra, where it terminates by dividing into the two common 



Trachea 



.. Left Common Carotid Artery 

 Scalenus Anticus Muscle 



.. Left Pneumogastric Nerve 



Left Subclavian Artery 



(Third Part) 

 Left Phrenic Nerve 



..Left Superior Intercostal 

 Artery 



__ Cervical Cardiac Branches 

 of Left Symp. and Vagus 

 _. Superficial Cardiac 

 Plexus 



_.. Left Bronchus 



FIG. 55. THE AORTA. 



iliac arteries. For convenience of description it is divided 

 into four parts : (1) The ascending aorta, (2) the arch of the 

 aorta, (3) the descending thoracic aorta, (4) the abdominal 

 aorta. 



