DISSECTION OF THE VASCULAR SYSTEM. 55 
of the thigh and the gastrocnemius; it represents the 
postervor tibial. 
we VHINS BELONGING TO LHE SYSTEM: OF 
THLE POS T-CAVA. 
1. The Post-cava (zzferzor vena-cava). Follow its 
course to the diaphragm. It receives no branches in 
the thoracic cavity. 
2. The Hepatic Veins. Where the cava pierces the 
diaphragm it receives two hepatic veins, one usually 
larger than the other. 
3. The Phrenic Veins empty into the cava at about 
the same level as the hepatic veins. They bring back 
blood from the diaphragm. 
4. The Renal Veins. Follow the post-cava along the 
dorsal wall of the abdomen. Att first it is partly im- 
bedded in the liver ; just below the liver it receives the 
two large renal veins coming directly from the kid- 
neys. The left is shghtly posterior to the right. 
5. The Spermatic (ovarzan) Veins, corresponding to 
the spermatic arteries. The one on the left side empties 
into the left renal vein, the one on the right side di- 
rectly into the cava. 
6. The Iliac Veins. Below the renal the cava re- 
ceives several veins from the muscles of the abdominal 
wall, and finally divides into two large branches, the 
common tliac vers. Each of these in turn divides 
into an external and an znternal zliac vern Which bring 
back blood from the regions supplied by the arteries of 
the same name. 
