Danio rerio anatomical entity duodenum AAO:0010402 BTO:0000365 CALOHA:TS-0214 EFO:0000851 EMAPA:18852 EV:0100073 FMA:7206 GAID:284 In fish, the divisions of the small intestine are not as clear, and the terms anterior intestine or proximal intestine may be used instead of duodenum. In humans, the duodenum is a hollow jointed tube about 10-15 inches (25-38 centimetres) long connecting the stomach to the jejunum. It begins with the duodenal bulb and ends at the ligament of Treitz. MA:0000338 MAT:0000044 MESH:A03.492.411.620.270 MIAA:0000044 NCIT:C12263 OpenCyc:Mx4rv4LJDpwpEbGdrcN5Y29ycA The first part of the small intestine. At the junction of the stomach and the duodenum the alimentary canal is inflected. The duodenum first goes anteriorly for a short distance, turns dorsally, and eventually caudally, thus it is a U-shaped structure with two horizontal sections (a ventral and a dorsal one). The fixed portion of the small intestine deeply lodged in the posterior wall of the abdomen and extending from the pylorus to the beginning of the jejunum. [Dorian_AF, Elsevier's_encyclopaedic_dictionary_of_medicine, Part_B:_Anatomy_(1988)_Amsterdam_etc.:_Elsevier][VHOG] UBERON:0002114 UMLS:C0013303 VHOG:0000052 XAO:0000236 duodenal galen:Duodenum http://upload.wikimedia.org/wikipedia/commons/b/b3/Tractus_intestinalis_duodenum.svg proximal intestine uberon upper intestine