The greater thoracic splanchnic nerves synapse primarily in the celiac and superior mesenteric ganglia, but some presynaptic fibers pass directly into the suprarenal medulla, to synapse there.
Parasympathetic fibers from the celiac branch of vagus also pass through these ganglia and the celiac and superior mesenteric plexi, to reach the organ wall to synapse. It is important to understand that these preaortic ganglia are sympathetic ganglia, so no parasympathetics would synapse there. Parasympathetic fibers synapse within the walls of the organ being innervated (with some exceptions in the head). | |