Blood supply to the gut

Question 1

what are the 3 arteries that the abdominal aorta splits into

Answer 1

Celiac trunk (at T12) supplying the foregut
Superior mesenteric artery (at L1) supplying the midgut
Inferior mesenteric artery (at L3) supplying the hindgut

Question 2

what does the coeliac trunk split into

Answer 2

The branches are the splenic artery, the left gastric artery and the (common) hepatic artery.

Question 3

what does the superior mesenteric artery split into

Answer 3

Its main branches are the jejunal arteries, the ileocolic artery, right colic artery and middle colic artery.

Question 4

what does the inferior mesenteric artery split into

Answer 4

Its main branches are the left colic artery, the sigmoidal arteries and the superior rectal artery

Question 5

what are arterial arcades

Answer 5

• the superior mesenteric artery gives 15-18 branches to supply the small bowel
• the branches unite to form loops or arches which are arterial arcades within the small bowel mesentery
• arcades give rise to straight arteries which as vasa recta

Question 6

when does a portal venous system occur

Answer 6

A PORTAL venous system occurs when a capillary bed drains to another capillary bed via veins.

Question 7

where is the hepatic portal vein formed

Answer 7

• formed at the level of L1 behind the neck of the pancreas

- by the junction of the splenic vein nd the inferior mesenteric vein

Question 8

what joints to form the superior mesenteric vein

Answer 8

• hepatic portal vein, splenic vein and inferior mesenteric vein

Question 9

where are the portal systemic anatomises

Answer 9

The distal oesophagus
The rectum
The posterior surface of the liver
The umbilicus

Question 10

what happens if there is raised pressure in the portal circulation

Answer 10

portal hypertension, consequent back pressure causes varices (abnormally dilated veins) at the sites of these porto-systemic anastomoses.