Duodenum

Question 1

What is the structure of the duodenum? What causes this course?

Answer 1

C-shaped

Passes around the head of the pancreas

Question 2

What are the start and end points of the duodenum?

Answer 2

Pyloric sphincter

Duodenojejunal flexure

Question 3

What structure supports the duodenojejunal flexure connecting the duodenum and jejunum to connective tissue surrounding the mesenteric and coeliac arteries?

Answer 3

Ligament of Treitz

Question 4

At what levels does the duodenum extend between? And what is its position in relation to the midline at these levels?

Answer 4

Start - L1 right of the midline
Middle - curves to the left of the midline
End - L2/3 right of the midline

Question 5

Describe the location of the duodenum in relation to the peritoneum.

Answer 5

Starts as an intraperitoneal organ and ends as a retroperitoneal organ

Question 6

The 1st division of the duodenum is overlapped by which 2 organs?

Answer 6

Liver and gall bladder

Question 7

Gall stones occasionally cause erosion and produce what structure between the gall bladder and duodenum? What is an associated risk of such a complication?

Answer 7

Choledocoduodenal fistula
Gallstone ileus (obstruction)

Question 8

Where are duodenal ulcers most commonly located?

Answer 8

The 1st part of the duodenum

Question 9

What are the likely secondary results of anterior duodenal ulcers and posterior duodenal ulcers?

Answer 9

Anterior - peritonitis as ulcer perforates into peritoneum
Posterior - haemorrhage as ulcer perforates into gastroduodenal artery or lumbar region pain as ulcer perforates into pancreas

Question 10

Describe the 2nd part of the duodenum

Answer 10

Descending, curves around the head of the pancreas and is retroperitoneal

Question 11

What is the major duodenal papilla and where is it located?

Answer 11

Opening of the main pancreatic duct (duct of Wirsung) into the duodenum
Halfway along the posteromedial aspect of the 2nd part of the duodenum

Question 12

What structure is found at the end of the main duodenal papilla

Answer 12

Sphincter of Oddi

Question 13

What can be located above the main duodenal papilla?

Answer 13

The opening of the accessory pancreatic duct (duct of Santorini)

Question 14

The main duodenal papilla is the marker of what transition?

Answer 14

Transition between embryonic foregut and midgut

Question 15

What arteries supply the duodenum?

Answer 15

Coeliac artery - foregut

Superior mesenteric artery - midgut

Question 16

What does ulceration in the 2nd part of the duodenum suggest?

Answer 16

Pancreatic disease or Zollinger-Ellison syndrome

Question 17

What is Zollinger-Ellison syndrome?

Answer 17

Gastrin-secreting tumour or hyperplasia of the islet cells in the pancreas
Overproduction of gastric acid causing recurrent peptic ulcers

Question 18

Describe the 3rd part of the duodenum

Answer 18

Level L2/3
Runs transversely
Crosses the aorta below the origin of the superior mesenteric artery

Question 19

What is the significance of the aorta and duodenum’s close positioning?

Answer 19

Development of aorto-duodenal fistula with upper GI haemorrhage

Question 20

What 2 structures are anterior and posterior to the duodenum?

Answer 20

Anterior - superior mesenteric artery

Posterior - aorta

Question 21

Describe SMA syndrome

Answer 21

Caused by dramatic weight loss
Aorta and superior mesenteric artery externally compresses the duodenum
Results in Duodenal obstruction (partial/complete)

Question 22

Describe the 4th part of the duodenum

Answer 22

Ascending part
Ascends to the left of the midline at level L1
Turns left
Retroperitoneal

Question 23

What does the 4th part of the duodenum form a sit turns left?

Answer 23

Duodenojejunal flexure

Question 24

Describe the ligament of Treitz and it’s functions

Answer 24

Fibrous ligament
Suspends and anchors the the duodenum, jejunum and duodenojejunal flexure
Contracts to aid peristalsis by widening the angle of the DJ flexure