Figure 1. General anatomy of the human liver: (a) upper surface; (b) lower surface. On the upper surface of the liver, two main lobes are distinguished, separated on their surface by a solid strand of connective tissue (‘ligament’). The lower surface (b) shows two other smaller lobes (quadrate and caudate lobes) as well as the location of the gallbladder, portal vein and hepatic artery. The tip of the gallbladder as well as the location of the portal vein are also shown in (a).

Figure 2. Functional segments of the human liver. The human liver can be divided into segments (indicated by Roman numerals), each containing a vascular supply and ducts for bile removal. Surgeons are guided by the functional division of the liver to resect one or more segments of the liver during an operation.

Figure 3. Cellular, vascular and biliary components of the liver. Hepatocytes, the main cells of the liver, form plates separated by sinusoids that are lined by endothelial cells, Kupffer cells and stellate cells. Blood flows from branches of the portal vein and the hepatic artery, located in the portal spaces (bottom of figure), to the central vein (top of figure). The bile duct system is composed of bile canaliculi, which are the spaces formed between adjacent hepatocytes, and of Hering canals, which are short channels that connect the bile canaliculi with small and large bile ducts located in the portal spaces. The Hering canals are lined by both hepatocytes and ductal cells around a central lumen. Bile flows towards the portal spaces, in the opposite direction of blood flow. Reproduced with permission from Junqueira et al. (1998).