Saturday, October 16, 2010
Myelination allows the Action Potential to jump down the axon.
The myelin sheath provides insulation for the neuron and increases the speed of the action potential transmission. For neurons with no sheath the speed of the action potential is proportional to the axon diameter (you may remember this from Krassen’s lectures in Biph2000).
The region of the axon covered in the sheath does not have any channels present in the membrane, they are instead localised to the nodes between the sheaths. In this way the potential can jump to each node with practically no loss of signal. This type of transmission is called “salutatory conduction”.
Information taken from: Molecular Cell Biology, Lodish, 6th edn, Chapter 23.
Image taken from: http://www.arts.uwaterloo.ca/~bfleming/psych261/lec4se21.htm
Posted by Heather at 12:13 PM