Duodenum Flashcards
First and shortest part of the small intestine
Widest and fixed part
C-shaped, about 10 inches long (25cm)
Begins at the pylorus on the right side and ends at the duodeno-jejunal junction on the left side (L2 vertebra)
DUODENUM
Divisions of duodenum
Superior (1st part) - 5cm & lies anterolateral to the body of L1
Descending (2nd part) - 7-10cm & descends along the right sides of L1 through L3
Horizontal (3rd part) - 6-8cm & crosses L3
Ascending (4th part) - 5cm & begins at the L of L3 and rises superiorly border of L2
Blood supply of duodenum
Upper part - SUPERIOR PANCREATICODUODENAL from gastroduodenal
Lower part- INFERIOR PANCREATICODUODENAL from superior mesenteric
Venous drainage of duodenum
SUPERIOR PANCREATICODUODENAL vein drains into portal vein
INFERIOR PANCREATICODUODENAL joins the superior mesenteric vein
Most often occur on the anterior wall of the first part of the duodenum followed by posterior wall
Duodenal ulcers
Occur most often with ulcers on the anterior wall; less often with ulcers on the posterior wall (May erode the gastroduodenal artery causing severe hemorrhage and perforate into the pancreas)
Perforation of the duodenum
25%
Male to female ratio = 1:1
Increase risk with blood type A
Bleeding from left gastric artery
Burning epigastric pain soon after eating; pain increases with food intake; relieved by antacids
LEFT GASTRIC ARTERY
Gastric ulcers
75%
Male to female ratio = 2:1
Increased risk with blood type O
Bleeding from gastroduodenal artery; perforation
Burning epigastric pain 1-3 hours after eating; pain decreases with food intake; relieved with antacids; patient wakes at night because of pain
GASTRODUODENAL ARTERY
Duodenal ulcer
The SUPERIOR MESENTERIC VESSELS may compress the horizontal part of the duodenum; patients experience EPIGASTRIC PAIN, NAUSEA after meal and bilious vomiting
Duodenal compression
Parts of duodenum
Superior
- INTRAPERITONEAL, has a mesentery (thus mobile)
- begins at pylorus which is marked by prepyloric vein
Descending
- retroperitoneal
- receives CBD & main pancreatic duct on its posterior or medial wall at hepatopancreatic ampulla
Horizontal
- retroperitoneal, across L3 between SMA anteriorly, aorta & IVC posteriorly
Ascending
- Intraperitoneal, ascends to meet jejunum at duodenojejunal flexure, supported by ligament of Treitz (this ligament is the cranial end of dorsal mesentery)
MC location: superior part of duodenum
Damage to mucosal barrier & acid hypersecretion due to H. Pylori (almost 100%)
Epigastric pain relieved by food
Tx: H2 blocker, PPI
Surgical procedure of choice: proximal gastric vagotomy which transects only the vagus nerve fibers to distal esophagus & gastric fundus
Duodenal ulcers
Usually occurs with ulcers on anterior surface of duodenum
Posterior surface (less common) –> erode gastroduodenal artery –> severe hemorrhage
Duodenal perforations
