Human digestive system the esophagus at its upper end and to the duodenum at its lower end. Gastric acid (informally "gastric juice"), produced in the stomach plays a vital role in the digestive process, and mainly contains hydrochloric acid and sodium chloride. A peptide hormone, gastrin, produced by G cells in the gastric glands, stimulates the production of gastric juice which activates the digestive enzymes. Pepsinogen is a precursor enzyme (zymogen) produced by the gastric chief cells, and gastric acid activates this to the enzyme pepsin which begins the digestion of proteins. As these two chemicals would damage the stomach wall, mucus is
National Institute of Diabetes and Digestive and Kidney Diseases Diseases Data System; National Digestive Diseases Data System; Kidney and Urologic Diseases Research Centers; and Digestive Diseases Research Centers. June 10, 1993—The NIH Revitalization Act of 1993 (P.L. 103—43) established the NIDDK as the lead Institute in nutritional disorders and obesity, including the formation of a research and training centers program on nutritional disorders and obesity. The act also provided for the directors of the National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institute on Aging, National Institute of Dental Research, and the NIDDK to expand and intensify research and related programs concerning osteoporosis, Paget's disease, and related