Posted by Nick Ahn on September 12, 2009 at 20:05:42:
this is from one of the questions that Dr. Zagon posted. please help me out.
T/F
The vagus nerve contains postganglionic parasympathetic nerves.
i'm leaning towards false
it is true that the vagus nerve is parasympathetic, and parasympathetic nerves are either collateral or intrinsic ganglia. if the vagus nerve was intrinsic the statement would be false because it is all preganglionic. if the vagus nerve contained some collateral ganglia, the statement could be true.
the vagus nerve comes out of the esophageal plexus as anterior (previously known as left) and posterior (was right) branches and they follow the esophagus through the esophageal hiatus in the diaphragm and enter the abdominal cavity. the anterior vagus nerve then runs in the anterior aspect of the stomach and goes to the hepatic plexus, innervating the liver, bile duct and all that junk. the posterior vagus nerve runs behind the stomach, deep to the peritoneum, and deep to the posterior wall of lesser sac and goes to the celiac plexus. and i now realize that this paragraph has nothing to do with my original question. i think it started off as my desperate attempt to justify my guess that the TF question was false, but apparently it didn't go anywhere but it was a good follow-through of the vagus nerves nonetheless. anyway, guys, help, please, anyone?