Comparison Of Graded Potential And Action Potential In Neurons

fefafiyi's version from 2015-09-02 08:22

Comparison of Graded Potential and Action Potential in Neurons

PropertyGraded PotentialAction Potential
l;l;l;Input SignalConduction Signal
Types of gated ion channels involvedMechanically, chemically, or voltage-gated channelsVoltage-gated channels only
Where occursUsually dendrides and cell bodyTrigger zone through axon
Ions involvedUsually Na+, Cl-, Ca2+Na+ and K+
Type of signalDepolarization (e.g. Na+) or hyperpolarizing (e.g. Cl-)Depolarizing
Strength of SignalDepends on initial stimulus; can be summedIs always the same; (all or none phenomenon); cannot be summed
What initiates the signalEntry of ions through channelsAbove-threshold graded potential at trigger zone
Unique characteristicsMinimum level required to initiate; two signals coming close together in time will sum; Initial stimulus strength is indicated by frequency of a series of action potentialsRefractory period; two signals too close together in time cannot sum