402 



ANGIOLOGY. 



Tight, passing out behind and between the pulmonary artery, and 

 the apex of the left auricular appendix, and immediately divides 

 into vertical and transverse branche?, with a distribution similar 

 to that of the right one. 



We will first consider the Posterior, afterwards the Anterior 

 Aorta 



POSTERIOR AORTA. 

 ^PlateV. 17.) 



The posterior aorta is larger and longer than the anterior. It ' 



Fig. 164. 



Thorax opened on the left side — showing the heart and large vessels in aitu. a a, Piericardial sac*; 

 6, Left ventricle ; c, Eight ventricle ; d, Left coronary artery : e, Primitive or common aorta ; «', 

 Anterior aorta ; c", Posterior aorta ; /, Pulmonary artery, divided and ligatured ; g, Anterior vena 

 cava ; h. Posterior vena cava ; i, Eight bracial, or brachio-cephalic artery ; k, Left brachial artery ; 

 I, Left dorsal artery, giving off the subcostal posteriorly ; m. Left superior cervical artery ; n, Left 

 vertebral artery ; o, Left inferior cervical artery ; p, Left external ; and q. Internal thoracic arteries. 



commences at about the level of the fourth dorsal vertebra, 

 passes upwards and backwards, forming the aortic arch, and reach- 

 ing the left side of the spine at the sixth or seventh dorsal ver- 

 tebra. It passes straight backwards to the hiatus aoi'ticus, entering 

 the abdomen between the pillars of the diaphragm, and terminat- 



