Abstract
Twenty livers of Japanese fetuses (more than five-months) were examined. The branches of the portal vein inside the liver were traced by simple dissection to investigate the arrangement of major portal branches.
The results were as follows:
1) At the hilus of the liver, the portal vein was divided into the right and left trunks in 6 cases, 30.0%. It was divided into the left trunk, the ramus lateralis inferior, and the ramus centralis in 5 cases, 25.0%. At the junction of the three branches, one branch arose in 9 cases, 45.0%.
2) The left trunk had the transverse and umbilical part, and at the junction of the two parts, the ductus venosus arose.
3) At the junction of the transverse and umbilical part, the ramus superior sinister arose. From the left wall of the umbilical part, the ramus intermedius and the ramus inferior sinister arose. The ramus superior sinister and the ramus inferior sinister existed in 16 cases, 80.0%. In addition to the two branches, the ramus intermedius existed in 4 cases, 20.0%.
4) At the junction of the transverse and umbilical part, the ramus quadratus superior arose. From the right wall of the umbilical part, the ramus quadratus medius and the ramus quadratus inferior arose. The ramus quadratus inferior only existed in 11 cases, 55.0%. In addition to this branch, the ramus quadratus superior existed in 5 cases, 25.0% and the ramus quadratus medius existed in 4 cases, 20.0%.
5) From the wall of the transverse part, several twigs arose.
