326 THE CIRCULATORY SYSTEM. 



iliac veins (Fig. 126, w). It passes craniad near the dorsal 

 median line, lying at first dorsad of the aorta (/?), then to the 

 right, then ventrad. It enters the substance of the liver in the 

 dorsal part of the caudate lobe of the latter, passes through the 

 liver, and then through the diaphragm near the ventrolateral 

 edge of the central tendon. It passes then craniad in the 

 thoracic cavity (Fig. 129, c) ventrad of the caudal lobe of the 

 right lung, and enters the right auricle. 



It receives the following branches (Fig. 126): lumbar, ilio- 

 lumbalis (7), spermatica interna (//), renal (/), adrenolum- 

 balis (i), phrenic, and hepatic veins. All but the last two 

 named accompany the arteries of the same name. 



V, phrenica. — The phrenic veins gather the blood from 

 the diaphragm and empty into the vena cava as it penetrates 

 the diaphragm. 



V. hepatica. — The hepatic veins vary in number. They 

 gather the blood from the liv^er (sent in by the portal vein and 

 hepatic arteries) and enter the vena cava just caudad of the 

 diaphragm. 



Vena Tort.e. The Portal Vein (Fig. 131). — The 

 portal vein is the large vein carrying the blood from the 

 abdominal viscera to the liver. Within the liver the portal 

 vein breaks up into capillaries; these collect to form the 

 hepatic veins, which enter the vena cava inferior. The portal 

 vein (a) is formed near the pyloric end of the stomach (1) by 

 the union of the superior mesenteric (d) and gastrosplenic (c) 

 veins and passes thence along the ventral border of the fora- 

 men epiploicum (foramen of Winslow) to the liver (2), where it 

 divides, going to the lobes of the liver. On its way to the 

 liver it may receive the pancreaticoduodenalis {d), gastroepi- 

 ploica (e), and coronaria ventriculi (/). These may unite with 

 the portal separately, or any two or all three may unite to form 

 a single trunk before entering the portal vein. 



1 . V. coronaria ventriculi (/) gathers the blood from the 

 lesser curvature of the stomach and anastomoses with the 

 gastrosplenic veins. It usually empties into the portal vein 

 near the pylorus. 



2. V. pancreaticoduodenalis (^/) receives the blood from 



