Preganglionic nerve fibers: Difference between revisions
Cmagedera1 (talk | contribs) m Minor grammar edit. |
Corrected factual error- preganglionic neurones may be either myelinated or unmyelinated- Added words "either unmyelinated or" to reflect this. |
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In the [[autonomic nervous system]], fibers from the [[central nervous system|CNS]] to the [[autonomic ganglion|ganglion]] are known as '''preganglionic fibers'''. |
In the [[autonomic nervous system]], fibers from the [[central nervous system|CNS]] to the [[autonomic ganglion|ganglion]] are known as '''preganglionic fibers'''. |
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All preganglionic fibers, whether they are in the [[sympathetic nervous system|sympathetic division]] or in the [[parasympathetic nervous system|parasympathetic division]], are both [[cholinergic]] (that is, these fibers use [[acetylcholine]] as their [[neurotransmitter]]) and [[myelin]]ated. |
All preganglionic fibers, whether they are in the [[sympathetic nervous system|sympathetic division]] or in the [[parasympathetic nervous system|parasympathetic division]], are both [[cholinergic]] (that is, these fibers use [[acetylcholine]] as their [[neurotransmitter]]) and either unmyelinated or [[myelin]]ated. |
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[[Sympathetic nervous system|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 nervous system|parasympathetic]] ganglia. Another major difference between the two ANS systems is divergence. Whereas in the parasympathetic division there is roughly 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. |
[[Sympathetic nervous system|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 nervous system|parasympathetic]] ganglia. Another major difference between the two ANS systems is divergence. Whereas in the parasympathetic division there is roughly 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. |
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Revision as of 15:02, 22 January 2013
| Preganglionic 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.
All preganglionic fibers, whether they are in the sympathetic division or in the parasympathetic division, are both cholinergic (that is, these fibers use acetylcholine as their neurotransmitter) and either unmyelinated or myelinated.
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 systems is divergence. Whereas in the parasympathetic division there is roughly 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
External links
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