Emergency Medical Technician (EMT) Intermediate Practice Exam

What is the chemical neurotransmitter of the parasympathetic nervous system?

1. Norepinephrine

2. Dopamine

3. Acetylcholine

4. Serotonin

The correct answer is: Acetylcholine

The chemical neurotransmitter associated with the parasympathetic nervous system is acetylcholine. This neurotransmitter plays a crucial role in the body's involuntary functions that promote a state of rest and recovery, such as lowering the heart rate, stimulating digestion, and facilitating glandular activities. Acetylcholine is released at the synapse between preganglionic and postganglionic neurons, as well as directly at the target organs innervated by the parasympathetic fibers. This function contrasts with that of norepinephrine, which is primarily linked to the sympathetic nervous system, facilitating the body's "fight or flight" response. Dopamine and serotonin are neurotransmitters involved in other physiological functions, including mood regulation and motor control, and are not primarily responsible for the parasympathetic responses. Thus, acetylcholine's role as the main neurotransmitter in the parasympathetic nervous system is integral to its ability to promote relaxation and restorative processes in the body.