Superior Portion of the Duodenum, Anterior View

Description

Arising immediately distal to the pylorus, the superior part of the duodenum (pars superior duodeni, D1) courses to the patient’s right and slightly posteriorly from the gastroduodenal junction. From an anterior direction, the proximal duodenal bulb sits inferior to the liver and gallbladder region, while the pyloric canal lies superior and medial to the first segment. The superior flexure marks the transition toward the descending part (D2) on the right side of the upper abdomen. Clean landmarks. Orientation of D1 matters because this short, mobile segment is the usual site of anterior duodenal ulcers, and its relationships explain bleeding and perforation patterns. An anterior ulcer can perforate into the peritoneal cavity, while posterior ulcers often erode the gastroduodenal artery running posterior to the first part, producing brisk upper gastrointestinal hemorrhage. Surgeons also rely on the anterior contour of the duodenal bulb when planning pyloroplasty or a Kocher maneuver to mobilize the duodenum and pancreatic head, where the hepatoduodenal ligament and biliary structures become immediate neighbors. Use this illustration for gross anatomy teaching of foregut derivatives, GI endoscopy orientation at the pylorus and duodenal bulb, and operative atlases discussing ulcer repair, antrectomy, or duodenal mobilization in trauma and pancreatic surgery. It also fits well in radiology and pathology texts that correlate the anterior profile of D1 with peptic ulcer disease distribution. Anatomical accuracy verified by SciePro's Medical Advisory Board.