Myelinated axons

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A [[Myelinated_axons|myelinated axon]] is one which is surrounded by a myelin sheath, comprised of [[Schwann cells|Schwann cells]]&nbsp;<ref>Lodish, Laisser, Bretscher, Amon, Berk, Krieger, Ploegh, Scott (2012) , Molecular Cell Biology, 7th Edition, New York, WH Freeman</ref>. &nbsp;It is electrically insulating, except for gaps in the sheath which are called the [[Nodes of Ranvier|Nodes of Ranvier]]. This insulation increases the speed of transmission of [[Action potential|action potentials]]. Due to the gaps in the myelin sheath, action potentials propagate by [[Saltatory conduction|saltatory conduction]], where action potentials jump between the nodes, where there is a higher abundance of ion channels. Conduction in myelinated axons is faster than transmission in an unmyelinated axon.&nbsp;
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A [[Myelinated_axons|myelinated axon]] is one which is surrounded by a myelin sheath, comprised of [[Schwann cells|Schwann cells]]&nbsp;<ref name="null">Lodish, Laisser, Bretscher, Amon, Berk, Krieger, Ploegh, Scott (2012) , Molecular Cell Biology, 7th Edition, New York, WH Freeman</ref>. &nbsp;It is electrically insulating, except for gaps in the sheath which are called the [[Nodes of Ranvier|Nodes of Ranvier]]. This insulation increases the speed of transmission of [[Action potential|action potentials]]. Due to the gaps in the myelin sheath, action potentials propagate by [[Saltatory conduction|saltatory conduction]]. Where action potentials jump between the nodes, there is a higher abundance of ion channels. Conduction in myelinated axons is faster than in an unmyelinated axon&nbsp;as the&nbsp;impluse 'jumps' from one Node of Ranvier to&nbsp;another<ref>Alberts B., Johnson A., Lewis J., Raff M., Roberts K. and Walters P. (2008). Molecular biology of the cell. 5th ed. New York: Garland Science. p680.</ref>.
  
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&nbsp;<ref>Alberts B., Johnson A., Lewis J., Raff M., Roberts K. and Walters P. (2008). Molecular biology of the cell. 5th ed. New York: Garland Science. p680.</ref>

Revision as of 21:47, 28 November 2013

A myelinated axon is one which is surrounded by a myelin sheath, comprised of Schwann cells [1].  It is electrically insulating, except for gaps in the sheath which are called the Nodes of Ranvier. This insulation increases the speed of transmission of action potentials. Due to the gaps in the myelin sheath, action potentials propagate by saltatory conduction. Where action potentials jump between the nodes, there is a higher abundance of ion channels. Conduction in myelinated axons is faster than in an unmyelinated axon as the impluse 'jumps' from one Node of Ranvier to another[2].

 

References

  1. Lodish, Laisser, Bretscher, Amon, Berk, Krieger, Ploegh, Scott (2012) , Molecular Cell Biology, 7th Edition, New York, WH Freeman
  2. Alberts B., Johnson A., Lewis J., Raff M., Roberts K. and Walters P. (2008). Molecular biology of the cell. 5th ed. New York: Garland Science. p680.

 [1]


Cite error: <ref> tags exist, but no <references/> tag was found
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