Human digestive system 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 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
National Institute of Diabetes and Digestive and Kidney Diseases National Institute of Diabetes and Digestive and Kidney Diseases The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) is part of the United States National Institutes of Health, which in turn is part of the Department of Health and Human Services. NIDDK is approximately the fifth-largest of the 27 NIH institutes. The institute's mission is to support research, training, and communication with the public in the topic areas of "diabetes and other endocrine and metabolic diseases; digestive diseases, nutritional disorders, and obesity; and kidney, urologic, and hematologic diseases". As of 2015, the Director of the institute is Dr.