Inferior Mesenteric Artery Flashcards

Review the inferior mesenteric artery, its aortic origin, descending course, major branches, hindgut supply, and collateral circulation.

Card 1 of 30Question

What is the inferior mesenteric artery?

An unpaired visceral branch of the abdominal aorta that supplies most of the hindgut.

In This Section

1. What is the inferior mesenteric artery?

An unpaired visceral branch of the abdominal aorta that supplies most of the hindgut.

2. From which vessel does the inferior mesenteric artery originate?

The abdominal aorta.

3. At approximately which vertebral level does the inferior mesenteric artery arise?

The L3 vertebral level.

4. From which surface of the abdominal aorta does the inferior mesenteric artery arise?

The anterior surface.

5. What is the position of the inferior mesenteric artery relative to the aortic bifurcation?

It arises superior to the aortic bifurcation.

6. Which embryological division of the gastrointestinal tract is primarily supplied by the inferior mesenteric artery?

The hindgut.

7. Which portions of the large intestine receive their principal arterial supply from the inferior mesenteric artery?

The distal transverse colon, descending colon, sigmoid colon, and upper rectum.

8. What are the three principal branches of the inferior mesenteric artery?

The left colic, sigmoid, and superior rectal arteries.

9. In which general direction does the inferior mesenteric artery travel after arising from the aorta?

Inferiorly and toward the left side of the abdomen.

10. What is the peritoneal relationship of the proximal inferior mesenteric artery?

It courses retroperitoneally before its branches enter the mesocolon.

11. Which branch of the inferior mesenteric artery primarily supplies the descending colon?

The left colic artery.

12. Into which two principal branches does the left colic artery commonly divide?

Ascending and descending branches.

13. Which artery typically anastomoses with the ascending branch of the left colic artery?

The left branch of the middle colic artery.

14. Which region of the colon is supplied by the ascending branch of the left colic artery?

The distal transverse colon and upper descending colon.

15. Which region is primarily supplied by the descending branch of the left colic artery?

The lower descending colon, with connections to the sigmoid arteries.

16. How many sigmoid arteries typically arise from the inferior mesenteric artery?

Usually two to four, although the number varies.

17. Within which peritoneal structure do the sigmoid arteries travel?

The sigmoid mesocolon.

18. Which artery is the terminal continuation of the inferior mesenteric artery?

The superior rectal artery.

19. At approximately which vertebral level does the superior rectal artery enter the pelvis?

Near S3, as it descends into the pelvis behind the rectum.

20. Into which principal branches does the superior rectal artery commonly divide?

Right and left branches that descend along the rectum.

21. Which arteries anastomose with the superior rectal artery to provide collateral circulation to the rectum?

The middle and inferior rectal arteries.

22. Which arterial network connects the territories of the superior and inferior mesenteric arteries along the colon?

The marginal artery of the colon, also called the marginal artery of Drummond.

23. What is the arc of Riolan?

A variable collateral arterial connection between the middle colic and left colic arterial systems.

24. Why is the splenic flexure considered a potential watershed region of the colon?

It lies near the junction of superior and inferior mesenteric arterial territories, where collateral flow may be limited.

25. What is Griffith's point?

A potential watershed area near the splenic flexure between the middle colic and left colic arterial territories.

26. What is Sudeck's point?

A potential watershed region near the rectosigmoid junction between the last sigmoid artery and superior rectal artery.

27. Which vein generally drains the intestinal territory supplied by the inferior mesenteric artery?

The inferior mesenteric vein, which usually drains into the splenic vein.

28. Which retroperitoneal structure must be protected during surgical dissection around the left colic artery?

The left ureter.

29. Why is the origin of the inferior mesenteric artery an important landmark during colorectal cancer surgery?

It guides vascular ligation and regional lymph node dissection during oncologic resection.

30. Why must collateral circulation be assessed when the inferior mesenteric artery is ligated?

Inadequate collateral perfusion may cause ischemia of the remaining colon or colorectal anastomosis.