Sinusoids

Sinusoids are the first blood vessels to form during hepatogenesis, and develop from existing vessels in the septum transversum mesenchyme. The sinusoids are comprised of hepatic sinusoidal endothelial cells and stellate cells. Blood plasma from the portal vein enters the sinusoidal space and comes into direct contact with the basal surface of hepatocytes, which absorb metabolites and toxins.Sinusoids, the smallest blood vessels in the adult liver, form a complex, three-dimensional plexus through which blood is transported throughout the liver lobules.