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.
