Multiple choice

Depolarization is caused by a ______ change in membrane permeability.

  1. slow

  2. normal

  3. equal

  4. rapid

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Depolarization is caused by a rapid increase in membrane permeability to sodium ions. Voltage-gated Na+ channels open suddenly in response to threshold stimulus, allowing Na+ to rush into the cell and rapidly change the membrane potential from negative to positive.