How does the depolarization at site A (after a stimulus) cause the propagation of the nerve impulse to site B?
1
The influx of Na+ at site A creates a current that flows from site A to site B, reversing the polarity at site B.
2
The outflow of K+ from site A spreads the depolarization to site B.
3
The efflux of Na+ at site A causes the hyperpolarization of the membrane at site B.
4
The action potential from site A is transmitted chemically to site B via neurotransmitters.