Duodenum has characteristic Brunner's gland which secrete two hormones called:

Brunner's glands are present in the duodenum region of small intestine. They secretes two hormones secretin and cholecystokinin. Oestrogen is secreted by ovary. Progesterone is secreted by corpus luteum. Prolactin is secreted by anterior pituitary. Parathormone is secreted by parathyroid gland. Related Theory Brunner's glands are located in the submucosa of the duodenum. They secrete an alkaline fluid containing mucin, which protects the mucosa from the acidic stomach contents entering the duodenum. It stimulates the release of digestive enzymes in the pancreas and stimulates the contraction of the gall bladder to empty bile into the duodenum.