I — Submucosa; 2 — Circular layer; 3 — Longitudinal layer; 4 = 2 + 3 — Muscular layer; Muscular coat; 5 — Major duodenal papilla; 6 — Pancreatic duct; 7 — Duodenum, descending part; 8 — Minor duodenal papilla; 9 — Accessory pancreatic duct; 10 — Circular folds;
II — Duodenum, superior part; 12 — Bile duct; 13 — Pyloric orifice; 14 — Pyloric sphincter; 15 — Body of pancreas; 16 — Superior mesenteric vein; 17 — Duodenojejunal flexure; 18 — Superior mesenteric artery; 19 — Duodenum, inferior part; horizontal part; transverse part;
20 — Jejunum; 21 — Head of pancreas
