DISSECTING MANUAL. 



of the left auricle; inferior interventricular vein (inferior or 

 middle cardiac) , running in the inferior interventricular sulcus 

 to the right end of the sinus. The anterior cardiac veins ascend 

 on the right ventricle, in front, and join the right coronary, or 

 end in the right auricle. The vence minima cordis drain the 

 heart walls and end in its cavities. [871] 



Superior Vena Cava. This is formed by both innominates 

 behind the first right costal cartilage. It descends behind the 

 aorta as far as the third right costal cartilage, and enters the 

 upper and back part of the right auricle. It receives the vena 

 azygos major, also pericardial and mediastinal veins. [871] 



Azygos Veins. The vena azygos major arises either from the 

 back of the inferior vena cava, opposite the right renal vein, 

 or as a continuation of the right ascending lumbar vein. 

 Ascending on the spine behind the right crus, it runs through 

 the aortic opening of the diaphragm ; then passing behind and 

 then arching forward over the root of the right lung, it ends in 

 the superior vena cava. It receives the right posterior (except 

 the first) and superior intercostal, right subcostal, right bron- 

 chial, oesophageal, pericardial, mediastinal, and superior and 

 inferior azygos minor veins. The vena azygos minor superior 

 is formed by the fourth to seventh left posterior intercostals. 

 Descending on the left of the spine, it crosses the seventh dorsal 

 vertebra, under the ossophagus and thoracic duct, to join the 

 azygos major. The vena azygos minor inferior is formed by the 

 left ascending lumbar, lower four posterior intercostal, left sub- 

 costal, and mediastinal veins. Ascending on the left of the 

 spine, it pierces the left crus, crosses the eighth dorsal verte- 

 bra under the thoracic duct and oesophagus, and joins the 

 vena azygos major. [872] 



Intercostal Veins. The anterior join the internal mammary 

 or musculo-phrenic. The posterior accompany the arteries; 

 the first joins the vertebral or innominate. On the right side 

 the second to fourth form a trunk (right superior intercostal) 

 which joins the azygos major; the rest join it separately. On 



[134] 



