Blood Supply Of The GI Tract

Question 1

Where does the abdominal aorta lie

Answer 1

Lies just to the left of the midline on the posterior abdominal wall

Question 2

Right and left common iliac arteries

Answer 2

Branches of the abdominal aorta
Supply the pelvis and lower limbs

Question 3

At what level does the aorta bifurcate

Answer 3

L4/5

Question 4

3 unpaired branches of the anterior aspect of the abdominal aorta

Answer 4

Coeliac trunk
Superior mesenteric artery
Inferior mesenteric artery

Question 5

At what level does the coeliac trunk branch from the aorta

Answer 5

T12

Question 6

At what level does the superior mesenteric artery branch from the aorta

Answer 6

L1

Question 7

At what level does the inferior mesenteric artery branch from the aorta

Answer 7

L3

Question 8

What does the coeliac trunk supply

Answer 8

Foregut: oesophagus, stomach, first 1/2 of duodenum, liver, gallbladder, pancreas, spleen

Question 9

What does the superior mesenteric artery supply

Answer 9

Midgut: second 1/2 of duodenum, Jejunum, ileum, caecum, appendix, ascending colon, proximal 2/3 transverse colon

Question 10

What does the inferior mesenteric artery supply

Answer 10

Hindgut: distal 1/3 transverse colon, descending colon, sigmoid colon, rectum

Question 11

3 branches of coeliac trunk

Answer 11

Left gastric artery
Splenic artery
Common hepatic artery

Question 12

Left gastric artery supplies…

Answer 12

Stomach

Question 13

Splenic artery supplies…

Answer 13

Spleen
Stomach
Pancreas- branches come off as travels to spleen

Question 14

Common hepatic artery supplies…

Answer 14

Liver
Gallbladder
Stomach
Duodenum

Question 15

Branches of superior mesenteric artery (SMA)

Answer 15

Jejunal and ileal branches
Ileocolic artery
Right colic artery
Middle colic artery

Question 16

Jejunal and ileal branches supply…

Answer 16

Jejunum and ileum

Question 17

Ileocolic artery supplies…

Answer 17

Ileum
Caecum
Appendix
Ascending colon

Question 18

Right colic artery supplies…

Answer 18

Ascending colon

Question 19

At what level is the aortic hiatus in the diaphragm

Answer 19

T12

Question 20

Middle colic artery supplies…

Answer 20

Transverse colon

Question 21

Branches of inferior mesenteric artery (IMA)

Answer 21

Left colic artery
Sigmoid branches
Superior rectal artery

Question 22

Left colic artery supplies…

Answer 22

Descending colon

Question 23

Sigmoid branches supplies…

Answer 23

Sigmoid colon

Question 24

Superior rectal artery supplies…

Answer 24

Rectum

Question 25

Mesenteric ischaemia

Answer 25

thrombus in a mesenteric artery (or one of its branches) leading to hypoperfusion of the segment of gut the vessel supplies. Can progress to infarction of the gut. Mortality is high.

Question 26

Ulcers of the stomach and duodenum

Answer 26

may erode through nearly vessels and cause severe intra-abdominal bleeding.

Question 27

Abdominal aortic aneurysm

Answer 27

part of the wall of the aorta weakens and bulges / expands. Rupture has a high mortality – older people, sudden onset severe abdominal / back pain, rapid bleeding, circulatory shock.

Question 28

Systemic veins

Answer 28

Carry venous blood directly to inferior vena cava Blood does NOT pass through liver

Question 29

Examples of systemic veins in abdomen

Answer 29

Renal veins Adrenal veins Hepatic veins

Question 30

Examples of paired branches of abdominal aorta

Answer 30

Renal arteries Gonadal arteries Lumbar arteries

Question 31

Unpaired branches of abdominal aorta

Answer 31

Celiac trunk Superior mesenteric Inferior mesenteric

Question 32

Left gastro-omental artery

Answer 32

Branch of splenic artery Supplies left border of stomach and part of omentum

Question 33

When does the common hepatic artery —-> hepatic artery proper

Answer 33

When gastroduodenal artery branches off

Question 34

What does the hepatic artery proper branch into

Answer 34

Right and left hepatic arteries

Question 35

What does the right gastro-omental arise from

Answer 35

Gastroduodenal from common hepatic artery

Question 36

What does the left gastro-omental arise from

Answer 36

Splenic artery

Question 37

Which arteries supply to greater curvature of the stomach

Answer 37

Right and left gastro-omental arteries Anastomose

Question 38

Which arteries supply the lesser curvature of the stomach

Answer 38

Left and right gastric arteries Anastomose

Question 39

Portal veins

Answer 39

carry nutrient-rich venous blood from the gut to the liver Blood then enters the hepatic veins and returns to the inferior vena cava

Question 40

Examples of portal veins

Answer 40

Superior and inferior mesenteric veins

Question 41

Portal system

Answer 41

Inferior mesenteric vein unites with splenic vein Splenic vein unites with superior mesenteric vein to form hepatic portal vein Hepatic portal vein enters liver Blood is processed, nutrients removed, and the venous blood then enters the hepatic veins, which join the inferior vena cava.

Question 42

Why don’t anastomosed vessels burst

Answer 42

Smaller branching arteries supply the surrounding viscera So blood is constantly removed

Question 43

Marginal artery

Answer 43

Anastomose of left colic and middle colic

Question 44

Liver metastases

Answer 44

from colon cancer – cancers of the colon often metastasize to the liver because venous blood from the colon is carried first to the liver via the portal system.

Question 45

Portal hypertension

Answer 45

high blood pressure in the portal system because of obstruction to flow through the portal vein or liver. Can lead to distended veins and bleeding at sites of portosystemic anastomoses.

Question 46

Order of portal system

Answer 46

Inferior mesenteric vein + splenic vein ——> + superior mesenteric vein ——> Hepatic portal vein ——> liver ——>hepatic veins (systemic) ——> inferior vena cava

Question 47

Venous drainage of distal oesophagus

Answer 47

BOTH Azygos —> superior vena cava AND Gastric veins —> portal veins —> liver —> inferior vena cava

Question 48

Branches of coeliac trunk clockwise

Answer 48

Left gastric Splenic Common hepatic

Question 49

Branches of superior mesenteric artery clockwise

Answer 49

Jejunal and ileal branches Ileocolic Right colic Middle colic

Question 50

Branches of inferior mesenteric artery clockwise

Answer 50

Left colic Sigmoid Superior rectal

Question 51

Name of anastomoses of left and middle colic arteries

Answer 51

Marginal artery

Question 52

Left portal vein supplies

Answer 52

Quadrate, caudate and left lobes of liver

Question 53

Right portal vein

Answer 53

Receives the cystic vein Supplies right lobe of liver

Question 54

At what level does the portal vein form

Answer 54

L2

Question 55

Where is the Meissner’s plexus located

Answer 55

Submucosa of small intestine