The Architecture of the Liver
The liver is the largest organ in the body. Liver tissue is composed of a compact mass of multisided units, known as the hepatic lobules. Each lobule consists of a central vein, which acts as a tributary of the hepatic vein and conducts processed blood away from the lobule, surrounded by plates of liver cells. The liver receives blood from two sources, 80 percent, which carries digested food materials, arrives from the intestine via the portal vein and venules; the remaining twenty percent is oxygenated blood from the heart, which enters through the hepatic artery and arterioles. An exchange of materials takes place between the liver cells and the blood, which then passes into the central veins and returns to the general body circulation via the hepatic vein. Sinusoids, spaces between plates of liver cells composed of tributaries of the hepatic artery and portal vein, conduct the blood flow to the central vein. The bile canaliculus carries bile juice from the liver to branches of the bile duct which convey bile from the lobules to the gall bladder. When an adult is at rest, about two and a half pints of blood flow through the liver each minute.