Foregut, Midgut, Hindgut

Question 1

Which organs sit within the foregut

Answer 1

Liver
Gallbladder
Oesophagus
Upper 1/2 of duodenum
Stomach
Pancreas
Spleen

Question 2

Which organs sit within the midgut?

Answer 2

Lower 1/2 of duodenum
Ileum
Jejunum
Caeceum
Ascending colon
Proximal 2/3 of tranverse colon

Question 3

Which organs sit within the hindgut?

Answer 3

Distal 1/3 of transverse colon
Descending colon
Sigmoid colon
Upper rectum

Question 4

Where are the lateral paracolic gutters? How are they formed? What is their clinical significance?

Answer 4

Spaces that lie between the lateral surfaces of the ascending and descending colons and the posterolateral abdominal wall. Formed as the ascending and descending colons are retroperitoneal structures.
Infection can spread via these spaces anywhere between the diaphragm and pelvic cavity.

Question 5

At what vertebral level is the oesophageal hiatus? What is it?

Answer 5

The point at which the oesophagus passes through the diaphragm to enter the abdominal cavity
T11/12

Question 6

At what vertebral level does the pylorus sit?

Answer 6

L1

Question 7

At what vertebral level does the head of the pancreas sit?

Answer 7

L2

Question 8

Which mesenteries attach to the foregut, midgut and hindgut?

Answer 8

Foregut: dorsal and ventral mesenteries

Midgut and hindgut: dorsal mesenteries only

Question 9

Where is the lesser omentum? What does it contain?

Answer 9

Peritoneum between the lesser curvature of the stomach and duodenum and the liver. Consists of 2 parts:

• Hepatogastric ligament (stomach to liver)
• Hepatoduodenal ligament (duodenum to liver) Contains bile duct, hepatic artery, hepatic portal vein

Question 10

Which arteries supply the duodenum?

Answer 10

Superior mesenteric artery via inferior pancreaticoduodenal artery
Coeliac trunk via gastroduodenal artery

Question 11

What type of muscle does the oesphagus contain?

Answer 11

Upper 1/3: skeletal (voluntary) muscle

Lower 2/3: smooth (involuntary) muscle

Question 12

Where does the oesophagus begin and end?

Answer 12

Distal laryngopharynx to lower oesophageal sphincter (gastro-oesophageal junction)

Question 13

What nerve supplies the foregut?

Answer 13

Vagus

Question 14

Where does the greater omentum extend from? What does it contain?

Answer 14

Extends from greater curvature of the stomach and proximal duodenum to the anterior surface of the transverse colon.
Contains fat, nerves, blood vessels, lymphatics

Question 15

What role does the greater omentum have?

Answer 15

Immunity: can migrate to infected viscera, isolates and limits the spread of intraperitoneal infections.

Question 16

What is the splenorenal ligament?

Answer 16

Layer of peritoneum connecting the spleen and left kidney, part of greater omentum

Question 17

What is the gastrosplenic ligament?

Answer 17

Layer of peritoneum extending from the greater curvature of the stomach to the spleen

Question 18

What is the Pringle manoeuvre?

Answer 18

Pinching of the hepatic artery and portal vein in the hepatoduodenal ligament of the lesser omentum to cut off blood supply to the liver in surgery

Question 19

At what vertebral level does the aorta pass through the diaphragm?

Answer 19

Approx T12

Question 20

What does the hepatoduodenal ligament contain?

Answer 20

Portal triad: hepatic artery, hepatic vein and common bile duct

Question 21

What is the ligament of Treitz? What is it a useful landmark for?

Answer 21

Attaches the distal part of the duodenum (duodenal-jejunal flexure) to the left crus of the diaphragm.
Useful landmark for duodenal-jejunal flexure and as a marker point for upper vs lower GI bleed.