Anterior view of the lower digestive tract, highlighting its extensive vasculature and its close relationship to the intestines and the liver. The main digestive function of the liver is the production of bile, a fat emulsifier, which is stored in the gallbladder until it is delivered to the duodenum when the stomach releases chyme, a thick semifluid mass of partly digested food. The liver also plays an important metabolic function. The extensive venal circulation of the intestinal tract comes together to form the hepatic portal vein, delivering nutrient-rich venous blood to the liver for processing.