Brunner's glands are submucosal glands located throughout the duodenum. The main function of it is to produce duodenum with an alkaline secretion (containing bicarbonate) in order to protect the duodenum from the acidic gastric contents. A gland is an organ in an animals body that synthesizes a substance for release such as hormones, often into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). ... In anatomy of the digestive system, the duodenum is a hollow jointed tube that connects the stomach to the jejunum. ... Bicarbonate is a polyatomic ion whose formula is HCO3-. It is the intermediate form in the deprotonation of carbonic acid: removing the first proton from carbonic acid forms bicarbonate; removing the second proton leads to the carbonate ion. ...