Human digestive system 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 duodenum where it is mixed with a number of enzymes produced by the pancreas. Saliva 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 papillae on the tongue and also from serous glands in the main salivary glands. Digestion is helped by the chewing of food carried out by the muscles of mastication, by the
National Institute of Diabetes and Digestive and Kidney Diseases (1927–1991) 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