Dividing liver tissue into lobules can be confusing, because the lobes are defined in different ways depending upon the function one is analyzing:
|"classic lobule||hexagonal, divided into centrilobular, midzonal, periportal parts||endocrine|
|"acinus||diamond shaped, divided into zone 3, zone 2, zone 1||blood/disease|
Sometimes the term "hepatic lobule" only refers to the "classic lobule".
When described as an "acinus lobule", the portal triad (portal vein, artery, bile duct) is at the centre and adjacent two central veins are at the periphery of the lobule. The liver parenchyma would be divided into zones based on oxygen supply. Zone 1 encircles portal tract where oxygen rich blood enters via hepatic arteries where as zone 3 being farthest has poorest oxygenation.