Vessels and nerves of the Midgut (Dave's notes)

Question 1

What vessel supplies the midgut?

Answer 1

The SMA

Question 2

List the seven branches of the SMA

Answer 2

Inferior pancreaticoduodenal
\+/- right hepatic
ileal branches (left)
jejunal branches (left)
ileocolic (right)
right colic (right)
middle colic (right)

Question 3

What are the boundaries of the midgut or SMA supply?

Answer 3

From the ampulla of vater to the splenic flexure

Question 4

What does the SMA lie on?

Answer 4

The left renal vein

Question 5

What developmental landmark is the SMA directed at?

Answer 5

The apex of the physiologic hernia

Question 6

What is the first branch of the SMA and its variants?

Answer 6

The interior pancreaticoduodenal - which may arise from the jejunal, and may give off the right hepatic

Question 7

What to the jejunal and ileal arteries form?

Answer 7

Arise from the left forming anastomosing arcades

Question 8

What are the branches of the ileocolic artery?

Answer 8

Arises from the right, giving off ileal and colic branches, then divides into the anterior and posterior caecal arteries

Question 9

What is the route of the right colic artery?

Answer 9

The right colic artery arises from the root of the mesentery and passes across the right psoas, gonadal vessels, ureter, and genitofemoral nerve

Question 10

Describe the course of the middle colic artery

Answer 10

The middle colic artery arises at the lower border of the neck of the pancreas then passes between the leaves of the transverse mesocolon. It lies to the right of the midline. On reaching the transverse colon it divides into left and right. A large avascular window is created on the left.

Question 11

At what level does the SMA arise?

Answer 11

L1

Question 12

Describe the venous drainage of the midgut

Answer 12

Each branch of the SMA is accompanied by a vein which coalesce to flow into the SMV