Pseudounipolar neuron
| Pseudounipolar neuron | |
|---|---|
 1: Pseudounipolar neuron; 2:Bipolar neuron | |
| Details | |
| System | Nervous system |
| Identifiers | |
| Latin | neuron pseudounipolare |
| TH | H2.00.06.1.00047 |
| Anatomical terms of neuroanatomy | |
Apseudounipolar neuronis a type ofneuronwhich has one extension from its cell body. This type of neuron contains anaxonthat has split into two branches. They developembryologicallyasbipolarin shape, and are thus termed pseudounipolar instead ofunipolar.[1]
Structure
[edit]A pseudounipolar neuron has oneaxonthat projects from thecell bodyfor relatively a very short distance, before splitting into two branches. Pseudounipolar neurons aresensory neuronsthat have nodendrites,the branched axon serving both functions.[2]The peripheral branch extends from the cell body to organs in the periphery including skin, joints and muscles, and the central branch extends from the cell body to thespinal cord.[3]
In the dorsal root ganglia
[edit]The cell body of a pseudounipolar neuron is located within adorsal root ganglion.[2]The axon leaves the cell body (and out of the dorsal root ganglion) into the dorsal root, where it splits into two branches. The central branch goes to thedorsal columnsof the spinal cord, where it formssynapseswith other neurons. The peripheral branch travels through the distaldorsal rootinto the spinal nerve all the way until skin, joint, and muscle.
In most sensory ganglia of cranial nerves
[edit]Pseudounipolar neurons are found in the sensory ganglia of mostcranial nerves.
Specifically the:
- trigeminal ganglion
- geniculate ganglion
- superior ganglion of the glossopharyngeal nerve
- inferior ganglion of the glossopharyngeal nerve
- superior ganglion of the vagus nerve
- inferior ganglion of the vagus nerve
Pseudounipolar neurons in cranial nerve sensory ganglia synapse in themain sensory trigeminal nucleus,spinal trigeminal nucleusorsolitary nucleus.
While thevestibulocochlear nervehas two ganglia associated with it (spiral ganglionandvestibular ganglion), both containbipolar neurons,not pseudounipolar.
In the mesencephalic nucleus
[edit]The mesencephalic nucleus is made up of pseudounipolar neurons which migrated into thebrainstemduring embryological development. It is the only location in thecentral nervous systemwhere the cell bodies of pseudounipolar neurons are found.
Function
[edit]All pseudounipolar neurons are sensory neurons. The ones found in the dorsal root ganglia, and majority of those in cranial nerve sensory ganglia carry information about touch, vibration, proprioception, pain and temperature.
Pseudounipolar neurons in the geniculate ganglion, inferior ganglion of theglossopharyngeal nerveand inferior ganglion of thevagus nervealso carry information about taste from taste buds.
Some of the pseudounipolar neurons in the inferior ganglion of the glossopharyngeal nerve carry information from thecarotid bodyandcarotid sinus.
The pseudounipolar neurons in themesencephalic nucleuscarry proprioceptive information from themuscle of mastication.
See also
[edit]References
[edit]- ^Gold, M. S.; Caterina, M. J. (2008-01-01), Masland, Richard H.; Albright, Thomas D.; Albright, Thomas D.; Masland, Richard H. (eds.),"5.04 - Molecular Biology of the Nociceptor/Transduction",The Senses: A Comprehensive Reference,New York: Academic Press, pp. 43–73,doi:10.1016/b978-012370880-9.00141-9,ISBN978-0-12-370880-9,S2CID83393483,retrieved2020-11-18
- ^abMacCallum, Don."Peripheral Nervous System".Histology and Virtual Microscopy Learning Resources.University of Michigan Medical School. Archived fromthe originalon 7 July 2014.Retrieved24 June2014.
- ^Kandel, Eric R.; Schwartz, James H.; Mack, Thomas M. Jessell (2000).Principles of neural Science(4th ed.). Cambridge: McGraw Hill. p.24.ISBN978-0838577011.