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Are there 3 divisions of the Autonomic Nervous System?

Discussion in 'Medical Students - MD' started by BlondeCookie, May 8, 2007.

  1. BlondeCookie

    BlondeCookie Senior Member 7+ Year Member

    Jul 4, 2005
    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?
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  3. irie

    irie royale with cheese 7+ Year Member

    Aug 21, 2003
    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.
  4. rup47

    rup47 5+ Year Member

    Jan 23, 2006
    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
  5. 45408

    45408 aw buddy 7+ Year Member

    Jun 13, 2004
    I'd go with parasympathetic and sympathetic. The enteric system is practically just fine all on its own.
  6. megadon

    megadon 5+ Year Member

    Aug 26, 2006
    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.
  7. browniegirl86

    browniegirl86 10+ Year Member

    Oct 12, 2004
    Portland, OR
    We learned the ENS as its own system, not part of the autonomic nervous system.

    So in my head:


    ENS = ENS
  8. EBI831

    EBI831 legend in the making 7+ Year Member

    Apr 18, 2006
    Chi-town royalty
    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).
  9. ivy91

    ivy91 Senior Member 5+ Year Member

    Oct 15, 2005
    New York
    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!

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