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| See [[Nodes of Ranvier|Nodes of Ranvier]] | | See [[Nodes of Ranvier|Nodes of Ranvier]] |
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| The interruptions in the myelin sheath were first discovered in 1878 by a French histologist and pathologist called Louis-Antoine Ranvier,who first described the nodes as constrictions. <ref>http://www.britannica.com/EBchecked/topic/417103/node-of-Ranvier</ref>
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| The Nodes of Ranvier are absolutely pivotal in the process of saltatory conduction. The Nodes themselves are approximately one micrometer in length apart, and they are the physical gaps between the myelin sheath cells themselves. <ref>https://psych.athabascau.ca/html/Psych289/Biotutorials/1/nodes.shtml?</ref> The action potential is able to jump from node to node along the axon, causing the transmission speed to reach around 120 metres per second. Each individually myelinated cell is referred to as a Schwann Cell.
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| The gaps are rich in ion channels, such as Sodium and Calcium channels, resulting in maximised speed at which ion mediators can be released into tissues and adjacent neurones. This is particularly handy at the synaptic cleft, (the area between a pre and a post synaptic neurone) because the quicker that sodium ions are released into the cell, the quicker that depolarisation can occur and the faster a response is produced as a result of the Action Potential that is caused. <ref>http://www.nature.com/nrn/journal/v4/n12/full/nrn1253.html</ref>
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| Overall, Myelination is a highly specialised property of axons and ensures that impulses travel at sufficiently high speed around the autonomic nervous system so that the body can produce a successful response.
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| <references />
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Latest revision as of 12:54, 24 November 2014