Blood Supply of Liver
The main blood supply of the liver comes from the portal vein, which gives it a special place in the control of metabolism. About 25-30% of total cardiac output at rest enters the sinusoids via terminal portal and arterial vessels. Of this, 70% comes from the portal vein, the remaining 30% is oxygenated blood, comes from the hepatic artery. The blood mixes, passes through the sinusoids and drains into the central vein. About 1.5 L of blood exit the liver every minute .
The viscera and liver are supplied by the coeliac, superior mesenteric, and inferior mesenteric arteries. The hepatic artery is a branch of the coeliac trunk. The portal vein is formed from the superior mesenteric and splenic veins in front of the inferior vena cava, behind the neck of the pancreas. Thus, it receives, almost all the products of digestion, absorption, and the hormones secreted by the pancreas. It is about 7-8 cm long and enters the liver via the porta hepatis. It differs from other veins since it has no valves and, in conditions such as cirrhosis, the flow can reverse.
The blood in hepatic portal veins is nutrient-rich but oxygen-poor, so it supplies the hepatocytes with nutrients. The oxygen supply is come from the hepatic artery, although the blood mixes while passing through the sinusoids. Blood in the sinusoids picks up plasma proteins, glycogens, and other processed or waste molecules produced by the hepatocytes, and enters central veins which eventually connect to inferior vena cava .
Fig. 6.12 Schematic illustration of the liver microstructure and the fabrication procedure of the hepatic cord-like micro-organoid by using the microfluidic system and the hydrogel microfiber. (a) Structure of the hepatic cord in the liver lobule. (b) Microfluidic system for fabricating sandwich- type alginate hydrogel microfibers that incorporate hepatocytes and 3T3 cells. (c) The formation process of hepatocyte-3T3 complex micro-organoids in the microfiber  (Copyright permission from Elsevier Science Ltd)