Human digestive system swallowing and vomiting to prevent the contents of the stomach from entering the esophagus. As the esophagus does not have the same protection from acid as the stomach, any failure of this sphincter can lead to heartburn. The esophagus has a mucous membrane of epithelium which has a protective function as well as providing a smooth surface for the passage of food. Due to the high volume of food that is passed over time, this membrane is continuously renewed. The diaphragm is an important part of the body's digestive system. The muscular diaphragm separates the thoracic cavity from the abdominal
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