Digestive system of gastropods species that have undergone de-torsion, however, the oesophagus may open into the anterior of the stomach, which is therefore reversed from the usual gastropod arrangement. In "Tarebia granifera" the brood pouch is above the oesophagus. There is available an extensive rostrum on the anterior part of the oesophagus in all carnivorous gastropods. Some basal gastropod clades have oesophageal gland. In most species, the stomach itself is a relatively simple sac, and is the main site of digestion. In many herbivores, however, the hind part of the oesophagus is enlarged to form a crop, which, in terrestrial pulmonates, may even replace
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.