Brunner's glands are unique to mammalian species and in eutherians are confined
primarilyto the submucosa of the proximal duodenum. In the majority of species examined,
they begin at the gastrointestinal junction and extend for variable distances distally in the
wall of the proximal small intestine. Ducts of individual glands empty either directly into the
intestinal lumen or unite with overlying intestinal glands (crypts of Lieberkühn) dependent on
the species. Secretory units of Brunner's glands consist of epithelial tubules that show …