"Immediately before reaching the liver, the portal vein divides in the porta hepatis into left and right portal veins. The right portal vein divides into anterior (supplying segments 5 and 8) and posterior (supplying segments 6 and 7) branches. The left portal vein may be divided into transverse and umbilical portions, as delineated by the ligamentum venosum, and is mostly extrahepatic in its course. The main branches of the left portal vein originate from the umbilical portion, and supply liver segments 2, 3 and 4 5."
"Sappey veins/periumbilical veins (left branch of the portal vein) 2,4"
"Abernethy malformation"
"The embryonic vitelline veins drain from the yolk sac to the sinus venosus. The two vitelline veins develop anastomosing cross-communications around the duodenum, in the developing liver and the septum transversum. Selective involution of these veins leads to the formation of the portal vein, and rotation of the foregut contributes to the formation of its extra-hepatic course 10."
Expected headings
"Terminology"
"Origin and course"
"Immediately before reaching the liver, the portal vein divides in the porta hepatis into left and right portal veins. The right portal vein divides into anterior (supplying segments 5 and 8) and posterior (supplying segments 6 and 7) branches. The left portal vein may be divided into transverse and umbilical portions, as delineated by the ligamentum venosum, and is mostly extrahepatic in its course. The main branches of the left portal vein originate from the umbilical portion, and supply liver segments 2, 3 and 4 5."
"There is an increased risk of bile duct hilar anatomical variation in the presence of portal vein variants."