The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (pancreas, liver, and gallbladder). In this system, the process of digestion has many stages, the first of which starts in the mouth. This produces a bolus which can be swallowed down the esophagus and into the stomach. Here it is mixed with gastric juice until it passes into the duodenum, where it is mixed with a number of enzymes produced by the pancreas. Gastric juice in the stomach is essential for the continuation of digestion as is the production of mucus in the stomach. This initially results in the production of chyme which when fully broken down in the small intestine is absorbed as chyle into the lymphatic system. Most of the digestion of food takes place in the small intestine. Water and some minerals are reabsorbed back into the blood in the colon of the large intestine. The waste products of digestion (faeces) are defecated from the anus via the rectum.