University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

452

Pages:

4
Author:

Mariam A. A.

Duodenum Position • 25-30 cm long • C-shaped around the head of the pancreas • L1-L3 level • The most proximal portion of the small intestine Parts Superior part: - Lies intraperitoneally - Connected to the liver via the hepatoduodenal ligament - Duodenal Cap/duodenal ampulla - Ends at the superior duodenal flexure and becomes the descending part Descending part - Retroperitoneally just like the other two parts - The bile and main pancreatic ducts enter its posteromedial wall. These ducts usually unite to form the hepatopancreatic ampulla (ampulla of vater, which opens on an eminence, called the major duodenal papilla - Minor duodenal papilla is proximal to major. ✓ - opening of the accessory pancreatic duct into the descending second section of the duodenum Transition from the descending to the horizontal part of the duodenum takes place at the inferior duodenal flexure Horizontal part - Inferior/third part - Runs from right to left ventrally from the abdominal aorta and the inferior vena cava Ascending part - Runs cranially along the left side of the vertebral column - Joins intraperitoneally lying the jejunum at the duodenojejunal flexure - Attached to the back of the abdominal wall through the suspensory ligament of the duodenum (ligament of Treitz) - Clinically the ligament of Treitz marks the border between the upper and lower gastrointestinal tract. Peritoneal attachment The duodenum is partly hidden by the root of the mesentery, which is the peritoneal attachment of the jejunoileum. Blood supply • Duodenal cap – right gastric artery and right gastroepiploic artery • Proximal to major duodenal papilla – gastroduodenal artery > superior pancreaticoduodenal artery • Distal to major duodenal papilla – superior mesenteric artery > inferior pancreaticoduodenal artery Venous drainage • Duodenal cap – prepyloric vein > portal vein • Rest of duodenum - superior pancreaticoduodenal vein > portal vein; inferior pancreaticoduodenal vein > superior mesenteric vein Innervation • Sympathetic: celiac and superior mesenteric sympathetic trunks • Parasympathetic: Vagus nerve