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Action Potentials
Propagation
Question | Answer |
---|---|
What is AP Propagation? | transfer along an Axon |
What is Saltatory Propagation? | repeated REGENERATION of AP's at each Node along an Axon |
What is the significance of Saltatory Propagation? | FASTER propagation velocity (skips though Axon), uses LESS ATP (Na+/K+ pump) |
What are the steps of Saltatory Propagation? | Stimulation --> Na+ gates OPEN --> Na+ INFLUX --> Depolarization --> + Ions flow away from activated area to next Node |
What is meant by Decremental? | 50% DECLINE in Amplitude in Saltatory Propagation |
What is the definition for Refractory Period? | time of membrane Depolarization and Hyperpolarization |
What is the significance of the Refractory Period? | 1. period of INSENSITIVITY to Stimuli; 2. limits maximum AP Frequency; 3. assures UNIDIRECTIONAL AP Propagation |
What would be the result of not have Nodes? | NO Nodes --> AP needs to open Na+ ans K+ channels themselves --> uses ATP and takes a lot of TIME |
What would happen if the nodes were further than 1mm apart? | current may be Subthreshold |