succus entericus The alkaline secretion produced by glands in the wall of the duodenum, consisting of water, mucoproteins, and hydrogencarbonate ions. It helps to counteract the highly acidic and proteolytic chyme entering the small intestine from the stomach, and thus protects the duodenum from damage. It was formerly believed to contain digestive enzymes, but duodenal enzymes are now known to be confined to cells of the brush border.

succus entericus See intestinal juice.