1042 



THE VASCULAK SYSTEM. 



forms the part of the left renal vein which crosses the front of the abdominal part of the aorta, 

 and the first two form that part of the inferior vena cava which extends from the liver to the 

 entrance of the renal veins. 



The Inferior Vena Cava. It follows, from what has been said, that the inferior vena cava is 

 a composite vessel derived from five sources : (1) the cephalic end of the right vitelline vein ; 



internal jugular vei 

 External jugular vein 



Vertebral artery 

 Left innominate vein 

 Subclavian artery 

 Subclavian 



Right pulmonary a 



Superior vena cava 

 Right atrium 



Vena azygos 

 Right ventricle 



Inferior vena cava, 

 vitelline vein portion 



Inferior vena cava, down- 

 growth from vitelline vein 

 Right and left branches 

 of portal vein 



Portal vein 



Remains of vitelline vei 

 Inferior vena cava 

 (subcardinal part)- 



Right renal vein 

 Right lumbar vein 



Inferior mesenteric artery 



Common iliac artery 

 External iliac artery 



1st aortic arch 

 "Internal carotid 



-2nd aortic arch 



External carotid 

 Internal carotid 



-, - J Arch of aorta 



Left subclavian artery 

 Left subclavian vein 

 _^, Ductus arteriosus 

 ~ ~ ~ "Pulmonary artery 



"""Left superior intercostal vein 

 "^--Left atrium 



Left ventricle 



Accessory hemiazygos vein 



Hemiazygos vein 

 Aorta 



Cceliac artery 



Spleen 

 Splenic vein 



.Superior mesenteric vein 

 ^Superior mesenteric artery 



-Kidney 



""- --Left renal vein 

 Umbilical vein 



^iLeft lumbar vein 



Placenta 



" Umbilical arteries 



Umbilical artery - 

 FIG. 839. DIAGRAM OF THE COURSE OF THE FCETAL CIRCULATION. 



(2) a caudal outgrowth from the cephalic part of the right vitelline vein; (3) a portion of the 

 right subcardinal vein ; (4) an anastomosis between the right subcardinal vein and the right 

 posterior cardinal vein ; and (5) a portion of the right posterior cardinal vein. 



The Veins of the Extremities. The primitive veins of the extremities are superficial vein 

 which run along the corresponding borders of the two limbs, i.e. the ulnar border of the upper and 

 the fibular border of the lower limb. 



The primitive vein of the upper extremity, which becomes the basilic vein, the axillary vein, 

 and the subclavian vein in different regions, opens at first into the posterior cardinal vein, after- 

 wards into the duct of Cuvier, and finally into the anterior cardinal vein. 



