This study aims at understanding the vascularization of the human liver to determine the correct way to divide it into "divisions" (sectors) and segments, for which we dissected 250 livers using the acrylic resin injection method. The results showed the role of the “Porta hepatis” in the hepatic vascular distribution, the existence of seven vascular pedicles for seven portal segments, and the role of portal fissures in the parenchymal division of the liver. Our research provides the definition of a portal segment and demonstrates the role of the hepatic portal vein in originating any liver parenchymal division.