Duodenal glands

Duodenal glands, or Brunner,s glands, are branched compound tubulo-alveolar mucous glands located within the submucosa of the duodenum, particularly in the proximal duodenum. They are most numerous in the first part of the duodenum and gradually decrease in number distally, occasionally extending into the proximal jejunum. Their ducts traverse the muscularis mucosae and open into the bases of the intestinal crypts (crypts of Lieberkühn).

Duodenal (Brunner's) glands secrete an alkaline, bicarbonate-rich mucus that neutralises acidic gastric chyme entering the duodenum from the stomach. This secretion protects the duodenal mucosa from acid-induced injury and creates a favourable pH environment for the activity of pancreatic digestive enzymes. In addition to mucus and bicarbonate, the glands produce substances such as urogastrone (epidermal growth factor), which contributes to mucosal protection and may inhibit gastric acid secretion.

Histological hallmark of duodenum

Histologically, Brunners glands are a distinctive feature of the duodenum and are an important criterion for identifying duodenal tissue microscopically. Their abundance in the submucosa distinguishes the duodenum from the jejunum and ileum, which lack these glands.