Crypts of Lieberkuhn is a gland found in the epithelial lining of the small intestine and colon. The pancreas is an endocrine organ that lies in the upper left abdomen. It is found behind the stomach, with the head of the pancreas surrounded by the duodenum. The suprarenal gland (adrenal gland) is located at the top of each kidney. The gastric gland is the basic secretory unit of the stomach and contains a variety of component cells located in different locations in the stomach.