• The liver is derived from a foregut endodermal bud which develops in the third week of gestation and divides into two parts: hepatic and biliary.
• The Couinaud classifi cation subdivides the liver into eight segments (segments I – IV in the left lobe, segments V – VIII in the right lobe) based on vascular and biliary anatomical landmarks.
• The lobule described by Kiernan is the most widely used unit of liver microanatomy, consisting of a hexagon - like region of liver parenchyma with a central vein as its hub and portal tracts located in the periphery of the hexagon.
• Hepatocytes are functionally heterogeneous within the lobular parenchyma, whereby centrilobular cells subserve different functions (e.g. drug metabolism) from periportal cells (e.g. bile salt - dependent bile formation).
• Uncomplicated regeneration of hepatocytes and/or bile duct epithelium usually occurs by cell division of the indigenous cells; however, when normal regenerative capacity is overwhelmed there may be activation of progenitors cells located in the region of the canals of Hering.
The liver, the largest organ in the body, weighs 1200 – 1500 g and comprises one - fi ftieth of the total adult body weight. It is relatively larger in infancy, comprising one - eighteenth of the birth weight. This is mainly due to a large left lobe.
