Autonomic nervous system - parasympathetic nervous system (Latin)

The origin of the systema nervosum parasympathicum is found within the medulla oblongata and the pars sacralis medullae spinalis. Like the sympathetic pathway, the parasympathetic pathway also consists of two neurons, the preganglionic (presynaptic) and postganglionic (postsynaptic) neurons, and parasympathetic ganglia. The presynaptic neurons of the systema nervosum parasympathicum are located within the medulla oblongata and pars sacralis medullae spinalis (S2-S4). These neurons send preganglionic fibers that synapse with the ganglia parasympathetica. In contrast to ganglion sympathicum, the ganglion parasympathicum is found near or within their target organs, which is why the parasympathetic preganglionic fibers are much longer than the sympathetic preganglionic fibers. The preganglionic fibers synapse with the postsynaptic neurons within the ganglia parasympathetica, which in turn project short postganglionic fibers to target organs, releasing the neurotransmitter acetylcholine.