Confused about acetylcholine

Premedgirl27

Full Member
2+ Year Member
May 8, 2015
230
133
California
  1. Pre-Medical
    Question was, "Which of the following is the primary neurotransmitter used by the parasympathetic nervous system"

    Answers:
    -acetylcholine
    -epinephrine
    -norepinephrine
    -dopamine

    I chose norepinephrine but the answer is acetylcholine. Why?
     

    aldol16

    Full Member
    5+ Year Member
    Nov 1, 2015
    5,300
    4,065
    1. Medical Student
      I chose norepinephrine but the answer is acetylcholine. Why?

      What do you mean by "why"? Why does the nervous system choose to use certain neurotransmitters for certain functions? Beats me. Likely has to do with an evolutionary stable state. But epinephrine and norepinephrine carry out the same effects - the "fight-or-flight" response. Epinephrine is more systemic whereas norepinephrine is more CNS-based.
       
      About the Ads

      David513

      Full Member
      5+ Year Member
      Dec 25, 2010
      105
      36
      1. Pre-Medical
        You could also have answered the question by asking, "Which one of these is not like the others?" Dopamine, norepinephrine, and epinephrine are all derived from tyrosine while acetylcholine is not. Dop., nor. and ep. are all catecholamines while ACh is not. Stimulant drugs increase the amount of transmission for dop, nor. and ep. but do not normally do so for ACh.

        But more directly to the question: ACh slows the heart down, which is a prime example of parasympathetic nervous system activation.
         

        Premedgirl27

        Full Member
        2+ Year Member
        May 8, 2015
        230
        133
        California
        1. Pre-Medical
          You could also have answered the question by asking, "Which one of these is not like the others?" Dopamine, norepinephrine, and epinephrine are all derived from tyrosine while acetylcholine is not. Dop., nor. and ep. are all catecholamines while ACh is not. Stimulant drugs increase the amount of transmission for dop, nor. and ep. but do not normally do so for ACh.

          But more directly to the question: ACh slows the heart down, which is a prime example of parasympathetic nervous system activation.

          Good point! thanks
           

          yeasureyoubetcha

          Full Member
          2+ Year Member
          Aug 12, 2015
          385
          244
          1. Medical Student
            I wonder if this has something do do with "primary" being pre-ganglionic neurons, in which case all autonomic preganglionic neurons have acetylcholine as their neurotransmitter. I thought where the sympathetic and parasympathetic differed was the postganglionic neuron. If I recall, sympathetic is NE and parasympathetic is acetylcholine. Maybe this is what was meant by primary?
             

            Cytarabine

            Full Member
            Mar 13, 2014
            1,012
            810
            1. Medical Student
              I wonder if this has something do do with "primary" being pre-ganglionic neurons, in which case all autonomic preganglionic neurons have acetylcholine as their neurotransmitter. I thought where the sympathetic and parasympathetic differed was the postganglionic neuron. If I recall, sympathetic is NE and parasympathetic is acetylcholine. Maybe this is what was meant by primary?

              It wouldn't change the answer
               

              DENTALSCHNEEZ811

              Full Member
              Jul 22, 2015
              383
              218
              1. Pre-Dental
                The presynaptic ganglion major neurotransmitter for both sympathetic and parasympathetic is Acytlcholine. The major transmitter for the post synaptic ganglion of the sympathetic branch is norepinephrine. The major transmitter for the postsynaptic ganglion of the parasympathetic is still Acetyl choline.


                Sent from my iPhone using SDN mobile
                 
                • Like
                Reactions: 1 user

                Premedgirl27

                Full Member
                2+ Year Member
                May 8, 2015
                230
                133
                California
                1. Pre-Medical
                  This thread is more than 5 years old.

                  Your message may be considered spam for the following reasons:

                  1. Your new thread title is very short, and likely is unhelpful.
                  2. Your reply is very short and likely does not add anything to the thread.
                  3. Your reply is very long and likely does not add anything to the thread.
                  4. It is very likely that it does not need any further discussion and thus bumping it serves no purpose.
                  5. Your message is mostly quotes or spoilers.
                  6. Your reply has occurred very quickly after a previous reply and likely does not add anything to the thread.
                  7. This thread is locked.