The liver is the largest organ of the body, and is composed of several lobes arranged around a central vein, a derivative of the hepatic vein. The functions of the liver are strongly linked to both the digestive as well as to the circulatory system. The liver produces bile that emulsifies fat and facilitates its absorption. Bile is stored in the gallbladder after its secretion by the bile canaliculi, and then discharged into the small intestine through the cystic duct. The liver also is the site of storage of excess food in the form of glycogen or lipid, which is released under hormonal influence into the blood as it is needed.
All vertebrates have a pancreas, which functions as both an exocrine and endocrine organ.
The exocrine part of the pancreas is the acinar gland, which produces digestive enzymes into the intestine.