Digestive System: Glandular Portion

Abstract

The numerous, small, intrinsic glands of the digestive system located in the mucosa or submucosa of the gastrointestinal tube (e.g., the minor salivary glands, gastric glands, duodenal submucosal glands, etc.) have been described in the previous chapter. An additional series ofglands, too large to be accommodated within the wall of the tract, develop by evagination of the mucosal epithelium entirely through the wall into adjacent tissues such as the facial connective tissue and the mesenteries of the duodenum. In each instance the original outgrowth remains as the major duct and the much-branched ends develop into large masses ofsecretory acini or, in the liver, cords and sheets of glandular tissue. These, the extrinsic glands, are the major salivary glands, pancreas, and liver.