 The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion, the tongue, salivary glands, pancreas, liver, and gallbladder. Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has many stages. The first stage is the subcaliq phase of digestion which begins with gastric secretions in response to the sight and smell of food. The next stage starts in the mouth. Chewing, in which food is mixed with saliva begins the mechanical process of digestion. This produces a bolus which can be swallowed down the esophagus to enter the stomach. Here it is mixed with gastric acid until it passes into the doodenum where it is mixed with a number of enzymes produced by the pancreas. Salina also contains a catalytic enzyme called amylase which starts to act on food in the mouth. Another digestive enzyme called lingual lipase is secreted by some of the lingual tuthuli on the tongue and also from sears glands in the main salad variclans. Digestion is helped by the chewing of food carried out by the muscles of mastication, by the teeth, and also by the contractions of peristalsis and segmentation. Gastric acid and the production of mucus in the stomach are essential for the continuation of digestion. Peristalsis is the rhythmic contraction of muscles that begins in the esophagus and continues along the wall of the stomach and the rest of the gastrointestinal tract. This initially results in the production of chym 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 theses are dedicated from the anus via the rectum.