The celiac plexus is a perivascular nerve plexus that lies along the celiac trunk and its branches. The paired celiac ganglia, which lie on the abdominal aorta beside the origin of the celiac trunk, receive presynaptic sympathetic fibers from the greater thoracic splanchnic nerves and perhaps the first lumbar splanchnic nerves. Most fibers synapse here and the postsynaptic fibers flow out along the celiac trunk and branches.
The celiac ganglia also receive presynaptic parasympathetic fibers from the celiac branch of the posterior vagal trunk. These fibers will NOT synapse in the celiac ganglia, which are sympathetic ganglia. These parasympathetic fibers merely pass through the celiac ganglia and plexus to reach the organ walls, where they synapse.
Some fibers from the celiac ganglia, both sympathetic and parasympathetic, pass down on the surface of the aorta to reach the adjacent superior mesenteric ganglion and plexus. | |