<prompt> What is Intrinsic Factor related to?Cobalamin absorptionVitamin DFolate absorbtionVitamin C  <response>: The gastric secretions arise from glands in the wall of the stomach that drain into its lumen, and also from the surface cells that secrete primarily mucus and bicarbonate to protect the stomach from digesting itself, as well as substances known as trefoil peptides that stabilize the mucus-bicarbonate layer. The glandular secretions of the stomach differ in different regions of the organ. The most characteristic secretions derive from the glands in the fundus or body of the stomach. These contain two distinctive cell types from which the gastric secretions arise: the parietal cells, which secrete hydrochloric acid and intrinsic factor; and the chiefcells, which produce pepsinogens and gastric lipase. The acid secreted by parietal cells serves to sterilize the meal and also to begin the hydrolysis of dietary macromolecules. Intrinsic factor is impoant for the later absorption of vitamin B12 or cobalamin. Pepsinogen is the precursor of pepsin, which initiates protein digestion. Lipase similarly begins the digestion of dietary fats.REF: GANONG;S REVIEW OF MEDICAL PHYSIOLOGY, KIM BARRETT, HEDDWEN BROOKS, SCOTT BOITANO, SUSAN BARMANTWENTY THIRD EDITIONPAGE NO:432 