PHGY 209 Lecture Notes - Lecture 16: Threshold Potential, Resting Potential
21 Feb 2018
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Document Summary
Axons propagate information from one region of the nervous system to another, by brief electrical impulses called action potentials: brief change (or spike) in membrane potential which lasts for 1-2 milliseconds. The membrane potential rises from it"s resting potential to a more positive level. Action potentials usually start at the initial segment of the axon and then propagate down the length of the axon to the presynaptic terminals. It is a specialized property of the axon (does not occur in dendrites) i. e tickling of the feet- when this occurs the neurons at the toes are activated and send impulses in waves through the action potentials. Used to describe the membrane potential at a more positive level ex. Used to describe the membrane potential becoming more negative ex. The action potential is a transient depolarizing spike that moves down the axon. The action potential is a brief depolarization and re-polarization of the membrane.
