PSYCO275 Lecture Notes - Myelin

• School: University of Alberta
• Department: Psychology
• Course: PSYCO275
• Professor: Deanna Singhal

Document Summary

Absolute refractory period is the first millisecond of the refractory period, where no matter whether or not you receive another signal high enough to cause another action potential. The second millisecond it is possible to open the channels, however, you will need much more positivity and a therefore an higher charge to cause this action potential. We need to keep the action potential unidirectional, and the absolute refractory period helps propagate the uni-directionality of the action potential by not allowing the sodium channels that have just opened to reopen. Maximum firing rate of 1000 times per second. Psps graded potentials, can be excitatory or inhibitory. Decremental the charge will degrade over time and distance. Nondecremental the initial voltage at the dendritic end is the same at the end of the terminal buttons, because the charge regenerates itself. Instant and decremental along each myelin segment to next node of ranvier.