Propagation of Action Potentials
Conduction: the movement of action potentials from their site of origin at a trigger zone to axon terminals
As Na+ flows into the cell, it causes voltage-gated Na+ channels to open in the adjacent segments of the membrane. Thus, the action potential travels along the membrane much like a row of dominos. It is actually the same AP; however, it just regenerates over and over at adjacent regions of the membrane from the trigger zone to the axon terminals. This is a positive feedback loop. In a neuron, this is a one-way street meaning the AP can only propagate away from the cell body. This is due to the absolute refractory period. Any region of the membrane that has just undergone an AP is temporarily unable to generate another one. Since the AP does not die out (non-decremental conduction), it can communicate over long distances in the body.
There are 2 types of propagation :
1. Continuous Conduction: described above and occurs in Unmyelinated Axons and in Muscle Fibres.
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