The Vascular System 205 
thin-walled vessel seen extending across the short 
space between the anterior face of the right 
lobe of the liver and the sinus venosus. As was 
also noted above, the hepatic veins, vh,—at any 
rate that from the left lobe of the liver,—enter the 
postcava so close to the heart that they may be 
considered to have one or more distinct openings 
into the sinus venosus. Followed caudad, the 
postcava may be traced through the large right lobe 
of the liver, from which it receives several branches. 
Emerging from the posterior border of the liver, 
it is seen to extend caudad, in the median line, as a 
rather inconspicuous vessel that receives blood 
from the reproductive organs and the kidneys that 
lie close on either side of it. 
The hepatic portal vein, h, has the usual distri- 
bution for that vessel. Entering the liver in the 
neighborhood of the bile duct, it receives first (2.e., 
nearest the liver) a small branch from the pan- 
creas, pv; near the pancreatic are one or two 
branches from the stomach, g, and a branch from 
the spleen, sp. A short distance caudad to these 
vessels are two or three mesenteric veins, m, 
leading from the mesentery and small intestine. 
Caudad to the mesenterics, the portal system may 
be seen as a vein of diminished caliber, i, leading 
from the posterior part of the small intestine and 
from the large intestine. 
The connection mentioned by Bronn between 
the rectal branch of the portal vein and the caudal 
