Sympathetic Innervation of the Abdomen Flashcards

Examine thoracolumbar sympathetic pathways, splanchnic nerves, prevertebral ganglia, visceral plexuses, and their effects on abdominal organs.

Card 1 of 30Question

Which spinal cord segments provide sympathetic outflow to the abdominal viscera?

The thoracolumbar spinal cord, primarily segments T5 to L2 for abdominal visceral pathways.

In This Section

1. Which spinal cord segments provide sympathetic outflow to the abdominal viscera?

The thoracolumbar spinal cord, primarily segments T5 to L2 for abdominal visceral pathways.

2. Where are the cell bodies of preganglionic sympathetic neurons located?

In the intermediolateral cell column of the spinal cord.

3. Through which spinal nerve roots do preganglionic sympathetic fibers leave the spinal cord?

The ventral roots of the spinal nerves.

4. Which communicating branches carry preganglionic sympathetic fibers into the sympathetic trunk?

The white rami communicantes.

5. How do most preganglionic sympathetic fibers destined for abdominal viscera pass through the sympathetic trunk?

They pass through the paravertebral ganglia without synapsing and continue into splanchnic nerves.

6. Which nerves carry most preganglionic sympathetic fibers from the thoracic sympathetic trunks toward abdominal ganglia?

The greater, lesser, and least thoracic splanchnic nerves.

7. Which thoracic sympathetic ganglia typically give rise to the greater splanchnic nerve?

The T5 to T9 sympathetic ganglia, with some anatomical variation.

8. Which prevertebral ganglia receive most preganglionic fibers from the greater thoracic splanchnic nerve?

The celiac ganglia.

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

The T10 and T11 sympathetic ganglia.

10. Which prevertebral ganglia commonly receive fibers from the lesser thoracic splanchnic nerve?

The aorticorenal and superior mesenteric ganglia.

11. Which thoracic sympathetic ganglion typically gives rise to the least splanchnic nerve?

The T12 sympathetic ganglion.

12. Which autonomic plexus commonly receives contributions from the least thoracic splanchnic nerve?

The renal plexus.

13. Through which part of the diaphragm do thoracic splanchnic nerves typically enter the abdomen?

They pierce the diaphragmatic crura.

14. Where are the major prevertebral sympathetic ganglia located?

Anterior to the vertebral column, around the abdominal aorta and origins of its major branches.

15. Which three major groups of prevertebral ganglia distribute sympathetic fibers to the gastrointestinal tract?

The celiac, superior mesenteric, and inferior mesenteric ganglia.

16. Which autonomic plexus primarily distributes sympathetic fibers to foregut organs?

The celiac plexus and its associated periarterial branches.

17. Which autonomic plexus distributes sympathetic fibers to the midgut?

The superior mesenteric plexus.

18. Which autonomic plexus primarily distributes sympathetic fibers to the hindgut?

The inferior mesenteric plexus.

19. Which nerves carry sympathetic fibers from the lumbar sympathetic trunks to abdominal and pelvic autonomic plexuses?

The lumbar splanchnic nerves.

20. How do postganglionic sympathetic fibers commonly reach abdominal organs?

They follow arterial branches as periarterial nerve plexuses.

21. Which autonomic plexus receives sympathetic fibers descending toward the pelvis near the aortic bifurcation?

The superior hypogastric plexus.

22. How does sympathetic stimulation generally affect gastrointestinal motility?

It decreases gastrointestinal motility and inhibits peristalsis.

23. What is the general effect of sympathetic stimulation on gastrointestinal secretions?

It reduces digestive glandular secretion.

24. How does sympathetic activation affect most blood vessels supplying abdominal digestive organs?

It produces vasoconstriction, reducing splanchnic blood flow.

25. How does sympathetic stimulation generally affect gastrointestinal sphincters?

It promotes contraction of many gastrointestinal smooth muscle sphincters.

26. Which neurotransmitter is released by preganglionic sympathetic neurons?

Acetylcholine.

27. Which neurotransmitter is released by most postganglionic sympathetic fibers supplying abdominal viscera?

Norepinephrine.

28. How does sympathetic innervation of the adrenal medulla differ from typical abdominal sympathetic pathways?

Preganglionic fibers synapse directly on chromaffin cells without an intervening postganglionic neuron.

29. Which nerve pathways carry most visceral pain afferents from the foregut and midgut toward the spinal cord?

Sympathetic pathways traveling through abdominal plexuses and thoracic splanchnic nerves.

30. What is the anatomical basis of a celiac plexus block for severe upper abdominal visceral pain?

It interrupts visceral pain transmission through nerve fibers surrounding the celiac trunk.