Most books (ex: Guyton Phys) classify the ANS as such: Parasympathetic Div Sympathetic Div Other books (ex: Netter's Clinical Anatomy) classify the ANS as such Parasympathetic Div Sympathetic Div Enteric Div I am a little confused about classifications of the Autonomic Nervous System (ANS). Who is right? Are there 2 ANS divisions or 3? Isn't the Enteric Div supposed to be part of the Parasympathetic Div? I hate it when I can't get my books to agree. Anyone know for sure?
Kinda. The enteric could be considered a seperate division but traditionally we just say Symp and parasymp. edit: Just know that the enteric plexuses can operate on their own.
Its been a while since physio but I believe that the confusion comes because that the enteric nervous system can control the gut independently from the CNS, even though it has connections to the CNS. I believe the connections are indirect and are primarily afferents to the CNS. so some may group it together as a subgroup of parasym. from the vagus and others may describe it as a distinct nervous system since it can function without inputs from the CNS hope this helps
I'd go with parasympathetic and sympathetic. The enteric system is practically just fine all on its own.
The enteric will continue operating if you cut both para and symp inputs. But it makes sense a lot of times to include it with ANS. In gross they didn't teach it, just knowing it existed was good enough. In phys you mostly talk about how para and symp affect GI stuff. We did talk a little bit about how it acts all on its own, but not too much (systematic peristalic waves, etc). So maybe in path or pathophys we'll cover it a bit more. Starting to sound like you don't need to know too much about it, huh? I wouldn't lose any sleep over this question.
We learned the ENS as its own system, not part of the autonomic nervous system. So in my head: ANS = PANS + SANS ENS = ENS
i'm gonna have to go with the symp and parasymp sys as the only 2 in the ANS. the enteric nervous system is separate and does not need innervation from the ANS; the ANS however can extrinsically affect the ENS indirectly by influencing the submucosal plexus and myenteric plexus actions but it is only these plexi that directly control the digestive system (long way to say the ENS is not part of the Parasymp sys).
On a sort of related note, the father of the enteric nervous system, Dr. Michael Gershon, is going to be on the Colbert Report on June 11th. He was one of my professors here, and I think Colbert will have a great time with him. Stay tuned!
