THE POSTEIIIOR VENA CAVA. 



707 



right gastro-omental, receiving ou its track yastric, splenic,, and omental hrancheSy 

 and joining the posterior mesenteric after passing above the left extremity of 

 the pancreas, and obtaining \\\.q posterior gastric vein (Fig. 390, 16). 



2. collateeal affluents of the 

 Vena Port^. 



A. Right Gastro-omental or Gas- 

 tro-epiploic Vein (Fig. 890, 15). — We 

 already know that the hepatic artery, be- 

 fore entering the liver, gives off pancreatic 

 branches, a pyloric branch, and a gastro- 

 omental division, which in turn detaches 

 a small duodenal artery ; the vessel de- 

 scribed as the rifiht gastro-omental vein 

 corresponds, in every respect, to all these 

 collateral ramifications of the hepatic artery. 



This vein, then, has its origin from 

 around the great curvature of the stomach, 

 but at an undetermined point, as it forms 

 an anastomotic arch with the left gastro- 

 omental vein. Posteriorly, it crosses the 

 dilatation at the origin of the duodenum, 

 receives the pi/Ioric, duodenal, smd pancreatic 

 veins, and opens into the vena portae after 

 traversing the pancreas. 



B. Anterior Gastric Vein. — Satel- 

 hte of the homonymous artery, this vein 

 joins the vena portte separately, after the 

 entrance of that vessel into the great pos- 

 terior fissure of the liver, and when very 

 near the terminal extremity of that fissiu'e.' 



Renal Veins. 



Two in number, like the arteries they 

 accompany, these veins are distinguished 

 by their enormous volume and the thin- 

 ness of their walls. The left, having to 

 cross the abdominal aorta before entering 

 the vena cava, is longer than the right. 

 They receive the majority of the veins from 

 the supra-renal capsules (Fig. 389, 10). 



Spermatic Veins. 



These vessels correspond to the sper- 

 matic arteries in the male, and the utero- 

 ovarian arteries in the female. 



Fig. 390. 



THE VENA PORT^ AND ITS ROOTS (PARTLY 

 THKORETICAI,). 



1, Trunk of the vena ])ortje ; 2, its origin ; 

 3, veins ot' the small intestine ; 4, ilio- 

 cascal vein ; 5, external ca>cal vein ; 6, 

 internal csecal vein; 7, anterior mesenteric 

 vein ; 8, 9, colic veins forming the roots 

 of that vessel; 10, collateral vein some- 

 times continuing the left colic, and 

 joining the anterior me>enteric vein near 

 its origin; 11, common confluent of the 

 posterior mesenteric ami sp>lenic veins; 

 12, posterior mesenteric vein and its 

 collateral branches; 13, splenic vein; 14, 

 left gastro-omental vein; 15, right ditto; 

 16, posterior gastric vein, a, Stomach ; 6, 

 duodenum; c, small intestine; d, cacum; 

 e, large colon; /, floating colon; g, rectum; 

 A, portion of the great omentum ; », 

 spleen ; j, mesentery ; k, colic mesentery. 



' Among these collateral affluents of the vena portae, it is necessary to mention the biliary 

 veins which Claude Bernard has injected in the Dog. These vessels, which correspond to the 

 hepatic artery, pass frnra the posterior surface of the liver, and open into the portal vein at a 

 short distance from that >;l>>nd. 



