Superior mesenteric artery

Question 1

what is the the superior mesenteric artery (SMA)?

Answer 1

a major artery of the abdomen

Question 2

where does the SMA arise from?

Answer 2

abdominal aorta

Question 3

what does the SMA supply?

Answer 3

supplies arterial blood to the organs of the midgut – which spans from the major duodenal papilla (of the duodenum) to the proximal 2/3 of the transverse colon

Question 4

what is the superior mesenteric artery numbered in terms of branches and where from?

Answer 4

The superior mesenteric artery is the second of the three major anterior branches of the abdominal aorta

Question 5

what are the 2 other branches of the abdominal aorta?

Answer 5

inferior mesenteric artery and coeliac trunk

Question 6

where does the SMA arise from in terms of the abdominal aorta?

Answer 6

It arises anteriorly from the abdominal aorta at the level of the L1 vertebrae, immediately inferior to the origin of the coeliac trunk

Question 7

what happens after the SMA has arose from the abdominal aorta?

Answer 7

the superior mesenteric artery descends down the posterior aspect of the abdomen

Question 8

what is anterior to the SMA?

Answer 8

pyloric part of the stomach, splenic vein and neck of the pancreas

Question 9

what is posterior to the SMA?

Answer 9

left renal vein, uncinate process of the pancreas and inferior part of the duodenum

Question 10

what is the only part of the pancreas that hooks around the back of the SMA?

Answer 10

The uncinate process

Question 11

what do the branches of the SMA supply?

Answer 11

the small intestines, cecum, ascending and part of the transverse colon

Question 12

what are the branches of the SMA?

Answer 12

inferior pancreaticoduodenal artery
jejunal and ileal arteries
middle & right colic artery
ileocolic artery

Question 13

what is the inferior pancreaticoduodenal artery?

Answer 13

The inferior pancreaticoduodenal artery is the first branch of the SMA

Question 14

what does the inferior pancreaticoduodenal artery form?

Answer 14

anterior and posterior vessels

Question 15

what do the anterior and posterior vessels of the inferior pancreaticoduodenal artery anastomose with?

Answer 15

branches of the superior pancreaticoduodenal artery

Question 16

where is the superior pancreaticoduodenal artery derived from?

Answer 16

coeliac trunk

Question 17

what does the network of the inferior pancreaticoduodenal artery and its anatomoses with superior pancreaticoduodenal artery supply?

Answer 17

supplies the inferior region of the head of the pancreas, the uncinate process, and the duodenum.

Question 18

what does the superior mesenteric artery give rise to? what do they supply?

Answer 18

The superior mesenteric artery gives rise to numerous arteries that supply the jejunum and ileum

Question 19

where do the arteries of the superior mesenteric artery pass between?

Answer 19

The arteries pass between the layers of the mesentery

Question 20

what forms after the arteries of the superior mesenteric artery has passed between the layers of the mesentery?

Answer 20

anastomotic arcades

Question 21

what arises from the anastomotic arcades and what do they supply?

Answer 21

smaller, straight arteries (known as the “vasa recta”) arise to supply the organs

Question 22

what is the jejunal blood supply characterised by?

Answer 22

characterised by a smaller number of arterial arcades, but longer vasa recta

Question 23

what is the ileal blood supply marked by in contrast?

Answer 23

the ileal blood supply is marked by more arterial arcades with shorter vasa recta

Question 24

where do the right and middle colic arteries arise from?

Answer 24

the right side of the superior mesenteric artery

Question 25

what does the middle colic artery supply?

Answer 25

transverse colon

Question 26

what does the right colic artery supply?

Answer 26

ascending colon

Question 27

what is the ileocolic artery in terms of branches of the superior mesenteric artery?

Answer 27

The ileocolic artery is the final major branch of the superior mesenteric artery. It passes inferiorly and to the right, giving rise to branches to the ascending colon, appendix, cecum, and ileum. In cases of appendectomy, the appendicular artery is ligated

Question 28

where does the ileocolic artery pass? (direction)

Answer 28

It passes inferiorly and to the right

Question 29

what does the ileocolic artery give rise to branches to?

Answer 29

giving rise to branches to the ascending colon, appendix, cecum, and ileum

Question 30

what are causes of superior mesenteric artery occlusion?

Answer 30

thrombosis, embolism, abdominal aortic aneurysm and aortic dissection

Question 31

what type of emergency is occlusion of the SMA?

Answer 31

acute

Question 32

why is occlusion of the SMA acute?

Answer 32

occlusion of the SMA restricts blood flow to the midgut, resulting in intestinal ischaemia

Question 33

what is occlusion of the SMA more common in?

Answer 33

elderly

Question 34

how does occlusion of the SMA present with?

Answer 34

abdominal pain

Question 35

what is the most useful investigation?

Answer 35

CT scan of the abdomen

Question 36

what is treatment for the occlusion of the SMA?

Answer 36

surgery