924 



HUMAN ANATOMY. 



3. Through the umbilical and siipraunibilical veins to the superficial or deep epigastrics and 

 so to the external iliac veins. It is interesting to note that in cases where this route is functional 

 the enlargement of the superficial epigastric veins is usually accompanied by a development of 

 varicosities upon them, while this is not the case with the deep epigastrics. An explanation of 

 this difference has been found in the fact that the deep veins, before opening into the external 

 iliac, bend slightly backward, so that their orifices are directed in the same way as the flow of 

 blood in the larger stem, whereas the superficial epigastrics open from above into the long 

 saphenous veins, their orifices being opposed, therefore, to the flow of blood in the saphenous, 

 — a condition which naturally predisposes towards stasis of the blood in the epigastrics and, it 

 may be remarked, also of that in the saphenous. 



These are the principal routes, but it must be noted that anastomoses also exist between 

 the portal system and the phrenic veins by means of the small veins which descend towards the 



Fig. 774. 



Suspensory ligament 

 of liver 



Round ligament 



of liver 



Vena cava inferior 



Portal vein 

 Pyloric vein 



Cystic-duct 



Coeliac axis 



Gall-bladder 



Gastro-duodenal vein 



Common bile-duct' 



Renal vein' 



Superior 



mesenteric vein 



Superior 



mesenteric artery 



Liver, under surface 



Spigelian 16be of liver 



Crura of diaphragm 



Aorta 



Phrenic vein 



Spleen 



Duodenum 



Ascending colon 



Caecun 



Gastric vein 



(which typically 

 passes farther to 

 the right to open 

 into the portal 

 vein; 



Kidney 



Splenic artery 



Left gastro- 

 epiploic vein 

 Splenic vein 



Renal vein 



Descending colon 



Inferior 



mesenteric vein 



Left colic vein 



Left spermatic vein 



Sigmoid vein 



Inferior 



mesenteric artery 



Superior 



hemorrhoidal \'ein 



Sigmoid colon 



Termination 



of ileum c^ 



edge of Cavity 01 pelvis 

 mesentery 



Inferior mesenteric and splenic veins and tributaries of portal vein ; stomach and 

 transverse colon have been removed and liver pulled upward. 



liver in the falciform ligament, and communications with the inferior caval system also occur 

 by means of retroperitoneal anastomoses between the peritoneal and mesenteric veins, both of 

 which are c}uite small. These communications are known as the veins of Rctziiis. 



Finally, it may be mentioned that anomalous and therefore inconstant communications of 

 the portal branches with those of other systems have been observed. Thus the gastric, the 

 short gastrics, or the pyloric vein may anastomose with the phrenics; the splenic or the left 

 gastro-epiploic with the renals ; the right or left colic with the branches from the fatty capsule of 

 liie corresponding kidney ; and the duodenal branches may open into the inferior vena cava. 



