Fig. 3: Schematic overview of the cellular composition and zonation of the liver in homeostasis.
From: Cell competition in primary and metastatic colorectal cancer
The liver is divided in three zones; Hepatic arteries, the portal veins and bile ducts are found closest to Zone I. Hepatocytes in zone I are exposed to the highest oxygen levels and are in the lowest WNT state. The transition area, Zone II, is where hepatocytes are characterized by absence of Zone I markers. Zone III hepatocytes surround the central vein and receive lower oxygen and nutrient input. Blood vessels are fenestrated, enabling exchange of nutrients, waste and oxygen. Liver resident macrophages (Kupffer cells) reside in the blood stream and stellate cells placed between the endothelium and hepatocytes in the space of Disse perform more general functions during development, regeneration and angiogenesis. Bile produced by hepatocytes is collected in the canaliculi between hepatocytes, and is accumulated in the bile ducts, which are surrounded by cholangiocytes.
