Parasympaticus is part of the autonomic nervous system and includes:
1/ preganglionic neurons located inside the CNS and transmitting filaments with cranial nerves 3, 7, 9, 10 and with spinal nerves S 2, S3, S4.
The preganglionic parasympathetic neurons are acetylcholine-producing and affect their postganglionic targets via their nicotin-sensitiveacetylcholine receptors
2/ postganglionic neurons out in the PNS in ganglia (terminal ganglia) and braids (plexus/an) connected to the above nerves.
The postganglionic parasympathetic neurons produce acetylcholine and affect their target cells via their muscarinsensitive acetylcholine receptors.
It is usually said that, in the parasympathetic nervous system, the preganlionic nerve fibers are long and the postganglionic filaments very short. The postganglionic cell bodies are usually embedded in the target organ itself.