Which of the following is the main reason that the opening of sodium channels causes a very rapid depolarization of most neurons?

Which of the following is the main reason that the opening of sodium channels causes a very rapid depolarization of most neurons?

Which of the following is the main reason that the opening of sodium channels causes a very rapid depolarization of most neurons?





  1. The movement of a sodium ion produces a larger voltage change than the movement of other ions.
  2. Sodium ion diffusion proceeds so quickly that whenever sodium channels are open, there is a rapid directional flux across the membrane.
  3. The conjunction of the sodium gradient and the negative membrane potential produces a very large driving force on sodium ions.
  4. All of the above
  5. None of the above

Answer: 3