Lesser Splanchnic Nerve Flashcards

Follow the lesser thoracic splanchnic nerve from the sympathetic trunk to abdominal ganglia, renal pathways, and visceral targets.

Card 1 of 25Question

What is the lesser splanchnic nerve?

A paired thoracic splanchnic nerve carrying predominantly preganglionic sympathetic fibers to abdominal prevertebral ganglia.

In This Section

1. What is the lesser splanchnic nerve?

A paired thoracic splanchnic nerve carrying predominantly preganglionic sympathetic fibers to abdominal prevertebral ganglia.

2. Which thoracic sympathetic ganglia typically contribute to the lesser splanchnic nerve?

The tenth and eleventh thoracic sympathetic ganglia (T10 and T11).

3. Which autonomic nervous system division is primarily represented in the lesser splanchnic nerve?

The sympathetic division.

4. Where are the cell bodies of preganglionic sympathetic neurons contributing to the lesser splanchnic nerve?

In the intermediolateral cell column of the thoracic spinal cord.

5. Through which communicating branches do preganglionic sympathetic fibers enter the thoracic sympathetic trunk?

The white rami communicantes.

6. Do preganglionic fibers of the lesser splanchnic nerve normally synapse in the thoracic sympathetic trunk?

No. They pass through the paravertebral ganglia without synapsing.

7. In which anatomical compartment does the lesser splanchnic nerve descend?

The posterior mediastinum.

8. In which direction does the lesser splanchnic nerve travel from the thoracic sympathetic trunk?

Inferomedially toward the diaphragm and upper abdominal prevertebral ganglia.

9. How does the lesser splanchnic nerve typically enter the abdomen?

By piercing the corresponding crus of the diaphragm.

10. Which prevertebral ganglia receive major contributions from the lesser splanchnic nerve?

The aorticorenal and superior mesenteric ganglia.

11. Where are the aorticorenal ganglia located?

Near the origins of the renal arteries on the lateral aspects of the abdominal aorta.

12. Which abdominal autonomic plexus surrounds the origin of the superior mesenteric artery?

The superior mesenteric plexus.

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

The midgut.

14. Which intestinal structures receive sympathetic innervation through the superior mesenteric plexus?

The distal duodenum, jejunum, ileum, cecum, ascending colon, and proximal transverse colon.

15. Which autonomic plexus connects the aorticorenal region to the kidneys?

The renal plexus.

16. Where do most preganglionic sympathetic fibers of the lesser splanchnic nerve synapse?

In abdominal prevertebral sympathetic ganglia.

17. How do postganglionic sympathetic fibers reach abdominal organs from the prevertebral ganglia?

They follow arterial branches within periarterial autonomic plexuses.

18. What is the general effect of sympathetic stimulation through the lesser splanchnic pathway on intestinal motility?

Decreased intestinal motility and inhibition of peristalsis.

19. How does sympathetic stimulation through the lesser splanchnic pathway affect intestinal blood vessels?

It generally produces vasoconstriction and reduces intestinal blood flow.

20. Which visceral sensory fibers may accompany the lesser splanchnic nerve toward the spinal cord?

Visceral pain afferents from midgut and upper abdominal structures.

21. Where are the cell bodies of visceral pain afferents traveling through the lesser splanchnic nerve located?

In the dorsal root ganglia of the corresponding thoracic spinal nerves.

22. How does the typical spinal origin of the lesser splanchnic nerve differ from that of the greater splanchnic nerve?

The lesser usually arises from T10 to T11, while the greater usually arises from T5 to T9.

23. Which thoracic splanchnic nerve typically arises inferior to the lesser splanchnic nerve?

The least thoracic splanchnic nerve, usually arising from T12.

24. What anatomical variation may occur between the lesser and least splanchnic nerves?

Their fibers may form a common nerve trunk, or the least splanchnic nerve may be absent.

25. Why is the lesser splanchnic nerve clinically relevant during thoracic splanchnicectomy?

It carries visceral pain afferents that may be interrupted to relieve severe abdominal visceral pain.