Innervation of the small intestine

Watch videos

The small intestine has an extrinsic and intrinsic innervation. The extrinsic innervation is facilitated via the sympathetic and parasympathetic divisions of the autonomic nervous system, the intrinsic innervation via the enteric nervous system.

Preganglionic sympathetic fibers from the thoracolumbar spinal cord travel as the greater and lesser thoracic splanchnic nerves to the celiac, aorticorenal and superior mesenteric ganglia. From there, postganglionic fibers are distributed via the celiac/superior mesenteric plexus to the duodenum, jejunum and ileum to inhibit digestion. Both the anterior and posterior vagal trunks of the vagus nerve send preganglionic parasympathetic contributions via the celiac ganglia which then follow the same pathway as the sympathetic fibers to stimulate digestion. Postganglionic parasympathetic fibers are located in the target organ wall.

The enteric nervous system regulates muscle tone and contractions, nutrient absorption and enzyme secretion via the myenteric plexus (plexus of Auerbach) and the submucosal plexus (Meissner's plexus).

Learn about the innervation of the small intestine in our video!

Take a quiz

Take the quiz below to consolidate your knowledge:

Test your knowledge with a broader topic focus and take our custom quiz about the entire neurovasculature of the abdomen!

Browse atlas

Explore each of the neural structures you have learned about in the gallery below.

Summary