Canaliculi are formed from spaces created when two hepatocytes are found adjacent to each other. Canaliculi are the beginning structures of the liver's bile duct system. The liver's bile flow is dependent upon the network that is created by the joining bile canaliculi. The flow of the bile duct system in the liver is opposite of its blood flow. Blood in the liver flows from the periphery to the center of the liver lobule. In contrast, the bile duct system flows from the center of the liver lobule to the periphery. The main function of the bile duct system of the liver is to excrete bile.