The liver plays a vital role in the metabolism of endogenous and exogenous substances. Its location between the gastrointestinal tract and the systemic circulation means that food and other consumed substances have to pass through the liver before reaching the systemic circulation. The liver receives blood from the gut via the portal vein (approx. 75%) and from the hepatic artery (approx. 25%). The blood from these vessels mixes at the entrance to the liver sinusoids which are specialised liver capillaries lined by highly fenestrated endothelial cells through which the majority of substrates can pass directly from the blood to the hepatocytes via an extended plasma volume, the space of Dissé. The vascular structure of the liver is thus optimal for the exchange of substances with the blood. From the sinusoids, the blood flows into the liver veins and is subsequently returned to the systemic circulation. The vascular structure and the interplay between its components is dynamic and of essential importance for the function of the liver.
Keywords: Hepatic artery; Portal vein; Liver sinusoids; Hepatic veins.