Learning Modules - Medical Gross Anatomy
Autonomics of the Abdomen - Page 6 of 16

    
The posterior vagal trunk is formed primarily by fibers of the right vagus nerve from the esophageal plexus. It passes through the esophageal hiatus to enter the abdomen, where it innervates the posterior surface of the stomach and sends an important branch to the celiac ganglia and plexus.

Presynaptic parasympathetic fibers generally synapse in the wall of the organ that they innervate. Many small, diffuse postsynaptic neurons within the organ walls then innervate smooth muscle, usually to cause peristalsis, and glandular cells, to cause them to secrete their products (secretomotor).

NOTE: The celiac branch delivers presynaptic parasympathetic for the GI tract between the stomach and splenic flexure of the colon. However, the celiac branch DOES NOT SYNAPSE in the celiac ganglion. These parasympathetic fibers will traverse the perivascular plexuses to reach organ walls before synapsing there, as is typical of parasympathetic fibers.

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