The duodenum.  Part 1: History, embryogenesis, and histologic and physiologic features. 
Long before the Christian era, the duodenum was named and its function in controlling gastric emptying was conjectured.  It received almost no further attention until the Eighteenth century when its relation to the bile and pancreatic ducts became know.  The embryogenesis of the duodenum and the histological features of the organ are described as well as the gross movements that explain the mature relations of the duodenum to the surrounding structures.  The "sphincters" of the duodenum are mentioned and evaluated.