Preganglionic nerve fibers
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| Preganglionic nerve fibers | |
|---|---|
 Autonomic nervous system innervation, showing the sympathetic and parasympathetic (craniosacral) systems, in red and blue, respectively | |
| Details | |
| Identifiers | |
| Latin | neurofibrae preganglionicae |
| TA98 | A14.2.00.009 |
| FMA | 76568 |
| Anatomical terms of neuroanatomy | |
In the autonomic nervous system, fibers from the CNS to the ganglion are known as preganglionic fibers.
Neruotransmitters
All preganglionic fibers in the parasympathetic division are cholinergic (that is, these fibers use acetylcholine as their neurotransmitter), which is also true for their postganglionic counterparts[1]. Those of the sympathetic division are adrenergic (use noradrenaline as their neurotransmitter), except for the postganglionic cutaneous sudomotor neurones, which are cholinergic.[2] All preganglionic neurons are myelinated.
Sympathetic vs Parasympathetic
Sympathetic preganglionic fibers tend to be shorter than parasympathetic preganglionic fibers because sympathetic ganglia are often closer to the spinal cord than are the parasympathetic ganglia. Another major difference between the two ANS (autonomic nervous systems) is divergence. Whereas in the parasympathetic division there is a divergence factor of roughly 1:4, in the sympathetic division there can be a divergence of up to 1:20. This is due to the number of synapses formed by the preganglionic fibers with ganglionic neurons.
See also
References
- ^ McCorry, Laurie Kelly (2007-08-15). "Physiology of the Autonomic Nervous System". American Journal of Pharmaceutical Education. 71 (4). ISSN 0002-9459. PMC PMCPMC1959222. PMID 17786266.
{{cite journal}}: Check|pmc=value (help) - ^ "Postganglionic nerve fibers", Wikipedia, 2018-11-27, retrieved 2019-04-21
External links
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