Small intestine + large intestine

Question 1

What spinal level does the duodenum sit at?

Answer 1

L1-3

Question 2

Which section of the duodenum is intraperitoneal?

Answer 2

Part 1 (superior portion)

Question 3

What marks the start of part 2 of the duodenum?

Answer 3

Major duodenal papilla

Question 4

Are the jejunum and ileum intraperitoneal or retroperitoneal organs?

Answer 4

Intraperitoneal

Question 5

What are the distinguishing features of the jejunum?

Answer 5

Thick intestinal wall
Longer vasa recta (straight arteries) 
Less arcades (arterial loops)
Red in colour 
Located in LUQ

Question 6

What are the distinguishing features of the ileum?

Answer 6

Thin intestinal wall 
Shorter vasa recta 
More arcades
Pink in colour 
Located in RLQ

Question 7

What is the blood supply to the duodenum?

Answer 7

Part 1 - gastroduodenal branch of the coeliac trunk

Parts 2-4 - inferior pancreaticoduodenal artery (branch of the SMA)

Question 8

What is the venous drainage of the duodenum?

Answer 8

Drain into hepatic portal vein

Question 9

What is the lymph drainage of the duodenum?

Answer 9

Pancreaticoduodenal and superior mesenteric nodes

Question 10

What is the blood supply to the jejunum and ileum?

Answer 10

Superior mesenteric artery

Question 11

What are arcades?

Answer 11

Branches of the superior mesenteric artery that anastamose to form loops supplying the jejunum and ileum of the small intestine

Question 12

What are vasa recta?

Answer 12

Long, straight arteries that arise from arcades to supply the jejunum and ileum of the small intestine.

Question 13

What is the venous drainage of the jejunum and ileum?

Answer 13

Superior mesenteric vein (which then drains into the hepatic portal vein)

Question 14

What is the lymph drainage of the jejunum and ileum?

Answer 14

Into the superior mesenteric nodes

Question 15

What is the ileocaecal valve?

Answer 15

Seperation of the small and large intestine.

Prevents reflux of enteric fluid from the colon into the small intestine

Question 16

Which parts of the colon are retroperitoneal?

Answer 16

Ascending and descending

Question 17

What are omental appendices?

Answer 17

Characteristic feature of the colon

Small pouches of peritoneum filled with fat

Question 18

What is the teniae coli?

Answer 18

Three strips of muscle running along the surface of the colon

Question 19

What are haustra?

Answer 19

Sacculations of the colon formed by contraction of the teniae coli

Question 20

What is the embryological origin of the colon?

Answer 20

Ascending colon and proximal 2/3 of the transverse colon are midgut structures
Distal 1/3 of the transverse colon, descending colon and sigmoid are hindgut structures

Question 21

What is the blood supply to the ascending colon?

Answer 21

Ileocaecal and Right colic branches of the SMA

Question 22

What is the blood supply to the transverse colon?

Answer 22

Right and middle colic branches of the SMA

Left colic branch of the IMA

Question 23

What is the blood supply to the transverse colon?

Answer 23

Left colic branch of the IMA

Question 24

What is the blood supply to the sigmoid colon?

Answer 24

Sigmoidal branches of the IMA

Question 25

What is the venous drainage of the colon?

Answer 25

Veins from ascending and transverse colon drain into SMA Veins from descending and sigmoid colon drain into IMV SMV and IMV empty into hepatic portal vein

Question 26

What is the nerve innervation of the colon?

Answer 26

Midgut structures = superior mesenteric plexus Hindgut structures = inferior mesenteric plexus (parasympathetic = pelvic splanchnic nerves, sympathetic lumbar splanchnic nerves)

Question 27

What is the lymph drainage of the colon?

Answer 27

Midgut structures = superior mesenteric nodes Hindgut structures = inferior mesenteric nodes Both drain into cisterna chyli which ultimately drains into the thoracic duct.

Question 28

What specialised tissue features does the small intestine have to aid digestion and absorption?

Answer 28

Mucosa has surface villi (finger-like projections) to increase surface area Each villus contains lymphatic channel known as lacteal Absorptive cells have microvilli (small projections of the plasma membrane) to increase surface area

Question 29

What is the Ligament of Treitz and its clinical relevancE?

Answer 29

Suspensory muscle of the duodenum | Marks the boundary between determining whether a GI bleed is classed as upper or lower