Duodenum
Discuss the parts of duodenum?
Duodenum (L. duodeni, twelve) was given its name because it is 12 fingerbreadths long (about 25 cms). All but the fist 2.5 cms of the duodenum is retroperitoneal. It forms a C shaped loop around the pancreas
Duodenum is divided into 4 parts
First part or superior part- the proximal half has a mesentery and is mobile. It lacks circular folds, giving the appearance of a “duodenal cap” on radiography. The distal half is immobile.
Second part or descending part- Bile and pancreatic duct opens in D2
Third part or horizontal part
Forth part or ascending part-this short part ascends and meets the body of pancreas and joins the jejunum at the duodenojejunal (DJ) flexure. The DJ flexure is supported by a fibromuscular band called the ligament of Treitz arising from the right crus of the diaphragm. At the DJ flexure, the intestine changes from a retroperitoneum (duodenum) to intraperitoneal position.
Discuss the blood supply of duodenum?
It is supplied by coeliac and superior mesenteric artery
The superior part of duodenum is supplied by
Superior pancreaticoduodenal branch of Supraduodenal artery
Right gastric artery (branch of hepatic artery)
Right gastroepiploic artery (branch of gastroduodenal artery arising from hepatic artery)
Gastroduodenal artery (branch of hepatic artery)
The inferior half of the duodenum is supplied by inferior pancreaticoduodenal artery (branch of superior mesenteric artery)
Discuss the lymphatic drainage of duodenum?
Pancreaticoduodenal nodes along the splenic artery and pyloric nodes along the gastroduodenal artery. Both of these nodes drain in coeliac nodes
Superior mesenteric nodes
Discuss the duodenal histology?
Same 4 layers as the rest of the GIT with the following exceptions:
The submucosa contain Brunner’s gland which produce copious alkaline mucus to neutralise the acid chyme entering from the stomach
The proximal duodenum shows few folding of the mucosal lining called valvulae conniventes. This increases in the distal end of the duodenum.
