Superior Mesenteric Plexus Flashcards

Explore the superior mesenteric plexus, its autonomic inputs, prevertebral ganglia, arterial branches, and midgut innervation.

Card 1 of 28Question

What is the superior mesenteric plexus?

An autonomic nerve network surrounding the superior mesenteric artery and its branches.

In This Section

1. What is the superior mesenteric plexus?

An autonomic nerve network surrounding the superior mesenteric artery and its branches.

2. Where is the superior mesenteric plexus located?

In the retroperitoneum around the origin of the superior mesenteric artery, anterior to the abdominal aorta.

3. At approximately which vertebral level is the superior mesenteric plexus centered?

L1, near the origin of the superior mesenteric artery.

4. Which sympathetic ganglion is closely associated with the superior mesenteric plexus?

The superior mesenteric ganglion, which may consist of variable ganglionic masses.

5. How is the superior mesenteric ganglion classified?

As a prevertebral sympathetic ganglion.

6. Which thoracic splanchnic nerve provides a major sympathetic contribution to the superior mesenteric plexus?

The lesser thoracic splanchnic nerve, typically associated with T10 and T11.

7. Which major autonomic plexus communicates superiorly with the superior mesenteric plexus?

The celiac plexus.

8. Which autonomic nerve network continues inferiorly from the superior mesenteric region along the abdominal aorta?

The intermesenteric plexus, part of the abdominal aortic plexus.

9. Which cranial nerve provides parasympathetic fibers to the superior mesenteric plexus?

The vagus nerve (cranial nerve X).

10. Which vagal pathway commonly carries parasympathetic fibers toward the superior mesenteric plexus?

The celiac branches of the posterior vagal trunk through the celiac plexus.

11. Where do preganglionic sympathetic fibers supplying the superior mesenteric plexus typically synapse?

In the superior mesenteric and associated prevertebral sympathetic ganglia.

12. Do preganglionic vagal parasympathetic fibers synapse in the superior mesenteric ganglion?

No. They pass through and continue toward terminal or intramural ganglia near or within target organs.

13. Which embryological division of the gastrointestinal tract receives autonomic fibers primarily through the superior mesenteric plexus?

The midgut.

14. What are the approximate proximal and distal boundaries of the gastrointestinal territory supplied by the superior mesenteric plexus?

From the distal duodenum to the proximal two-thirds of the transverse colon.

15. Which portions of the small intestine receive autonomic fibers through the superior mesenteric plexus?

The distal duodenum, jejunum, and ileum.

16. Which portions of the large intestine are supplied through branches of the superior mesenteric plexus?

The cecum, appendix, ascending colon, and proximal two-thirds of the transverse colon.

17. How do autonomic fibers from the superior mesenteric plexus reach the intestinal wall?

They follow branches of the superior mesenteric artery within periarterial nerve plexuses.

18. Which periarterial plexuses accompany the jejunal and ileal arteries?

The jejunal and ileal plexuses.

19. Which branch of the superior mesenteric plexus accompanies the ileocolic artery?

The ileocolic plexus.

20. Which periarterial plexus supplies autonomic fibers along the right colic artery?

The right colic plexus.

21. Which periarterial plexus distributes autonomic fibers along the middle colic artery?

The middle colic plexus.

22. Which arterial branch carries autonomic fibers from the superior mesenteric plexus toward the inferior pancreatic head and distal duodenum?

The inferior pancreaticoduodenal artery.

23. How does sympathetic stimulation through the superior mesenteric plexus generally affect intestinal motility?

It inhibits intestinal motility and reduces peristalsis.

24. What is the general effect of sympathetic stimulation on blood vessels supplying the midgut?

Vasoconstriction, which can reduce intestinal blood flow.

25. How does parasympathetic stimulation through the superior mesenteric plexus generally affect intestinal function?

It promotes intestinal motility and digestive secretion.

26. Which visceral sensory fibers commonly accompany sympathetic pathways through the superior mesenteric plexus?

Visceral pain afferent fibers from midgut structures.

27. Where is visceral pain from the midgut commonly referred?

The periumbilical region, corresponding primarily to the T10 dermatome.

28. Why is the superior mesenteric plexus clinically relevant during surgery near the superior mesenteric artery?

Dissection around the artery can injure autonomic fibers involved in intestinal motility, secretion, and vascular regulation.