The duodenum is the shortest and widest part of the small intestine. It is C-shaped and passes behind the pancreas and liver before joining the jejunum. The duodenum has four parts that have different peritoneal relations and visceral connections. It receives blood supply from the pancreaticoduodenal arteries and innervation from the sympathetic and parasympathetic nervous systems. Common clinical issues involving the duodenum include ulcers, diverticula, obstructions, and inflammation.

2.  Definition
 Parts of duodenum
 Peritoneal relation of the duodenum
 Visceral relation of the duodenum
 Internal openings in 2nd part of duodenum
 define ligament of treitz
 Blood supply and venous drainage
 Innervation and lymphatics
 Clinical anatomy: duodenal ulcer, diverticulum, duodenal obstruction,
duodenitis.

7.  Is the shortest, widest and the most fixed part of small intestine
 Location: umblical region , L1-L3 vert,
 Is C-shaped structure
 25 cm long
 Lacks mesentery and attached to posterior abdominal part
 Has 4 parts
1st part, superior part, 5 cm long
2nd part, descending part, 7.5 cm long
3rd part, horizontal part, 10 cm long
4th ,part, ascending part , 2.5 long

10.  Begin: continuation of pylorus
 Passes backward, upward and to right and take sharp curve downward.
 End: superior duodenal flexure
 Proximal 2.5cm is attach to lesser omentum above and greater omentum below.
 Distal 2.5cm is fixed. It is retro peritoneal. Covered with peritoneum only
anterior.
 VISCERAL RELATION:
 Anterior: quadrate lobe of liver, gall bladder
 Posterior: gastroduodenal artery, bile duct and portal vein
 Superior: epiploic foramen
 Inferior: head and neck of pancreas

12. RELATION:

13.  BEGIN: from duodenal flexure
 Runs downward to reach the lower border of 3 lumbar vert, curves to left
 END: inferior duodenal flexure
 Is retroperitoneal
 VISCERAL RELATION:
 ANTERIOR: right lobe of liver, transverse colon, root of transverse
mesocolon, small intestine
 POSTERIOR: right kidney anterior surface, right renal vessel, IVC, psoas
major
 MEDIAL: head of pancreas, bile duct
 LATERAL: right colic flexure

15. INTERNALLY:
 Posteromedially:
elevation called
hepatopancreatic
ampulla/ MAJOR
DUODENAL PAPILLA.
8-10cm distal to
pylorus.
 minor duodenal
papilla, opening of
accessory pancreatic
duct. 6-8 cm distal to
pylorus

17.  BEGIN: inferior duodenal flexure
 Runs horizontally slightly upward in front of inferior vena cava, and takes
upward turn in front of abdominal aorta.
 ENDS: in front of aorta by joining fourth part
 Is retroperitoneal and fix
 VISCERAL RELATION:
 ANTERIOR: superior mesenteric vessels, root of mesentery
 POSTERIOR: ureter (R), psoas major (R), testicular & ovarian vessels (R), IVC,
Aorta, inferior mesenteric artery.
 SUPERIOR: head of pancreas
 INFERIOR: jejunum

19.  Runs upward immediately to left of aorta up to upper border of L2 vert.
 Runs forward to join jejunum at duodenojejunal flexure.
 Is related to peritoneum anteriorly.
 VICERAL RELATIONS:
 ANTERIOR: transverse colon, transverse Mesocolon, lesser sac, stomach
 POSTERIOR: psoas major (l) renal vessel (L), testicular vessel (L),
inferior mesenteric vein, sympathetic chain (L).
 RIGHT: root of mesentery
 LEFT: kidney and ureter
 SUPERIOR: pancreas

20. Is fibromuscular band which suspends and supports the
duodenojejunal flexure.
Arise from right crus of diaphragm, close to right side of
oesophagus, passes downwards behind pancreas
Attach to posterior surface of duodenojejunal flexure and some
part of 3rd and 4th part of duodenum.

24. Superior –pancreatico duodenal artery branch of
gastro duodenal artery
Inferior- pancreatico duodenal artery branch of
superior mesenteric artery
First part also receives:
Right gastro epiploic artery
Left gastro epiploic artery

28.  Sympathetic: T9-T10 segments
 Para sympathetic: vagus nerve

29. Duodenal ulcer
Duodenal diverticulum
Duodenal obstruction
Duodenitis

30. Duodenal ulcer:

31.  A duodenal ulcer is
disruption of the mucosal
integrity of the duodenum
leading to a submucosal
exposure

32. DIVERTICULUM

33.  It is pouch like structure attach to the duodenum, first part of the
small intestine just pass the stomach
 2 types:
 Intramural and extramural
 It is usually asymptomatic
 found incidentally on routine imaging
 Complications are rare in duodenal diverticulosis but have been
reported, including but not limited to: small bowel obstruction (more
common with intraluminal diverticula), diverticulitis, and
gastrointestinal bleeding.

35.  Causes:
 Common site : opening of bile duct
 An annular pancreas
 Pressure by Superior mesenteric artery
 Contraction of the suspensory muscle of the duodenum

36. Duodenal atresia
• the congenital absence or complete
closure of a portion of the lumen of
the duodenum.
• It causes increased levels of
amniotic fluid during pregnancy
(polyhydramnios) and intestinal
obstruction in newborn babies.
• Treatment includes suctioning out
any fluid that is trapped in the
stomach, providing fluids
intravenously, and surgical repair of
the intestinal closure.

37. Radiography shows a
distended stomach
and distended
duodenum, which are
separated by the
pyloric valve, a
finding described as
the double-bubble
sign.

39.  Annular pancreas is a rare condition in which the second part of the duodenum is surrounded by
a ring of pancreatic tissue continuous with the head of the pancreas. This portion of the pancreas
can constrict the duodenum and block or impair the flow of food to the rest of the intestines.

43. A
B
D
E
F