Confused about acetylcholine

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Premedgirl27

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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?

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Epinephrine and norepinephrine are the primary neurotransmitters in the sympathetic nervous system- I associate adrenaline with fight or flight! Acetylcholine is for the parasympathetic nervous system.

Admittedly I don't have a great answer as to "why" :)
 
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.
 
Oh ok for some reason I thought epinephrine was for sympathetic response and norepinephrine was for parasympathetic response. Thank you
 
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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.
 
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
 
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?
 
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
 
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.


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just to note- it's also the main neurotransmitter in the somatic nervous system! I got tripped up on this today and I thought of this post so I wanted to add it here :)
 
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