Question

Let's consider a scenario in which the resting membrane potential changes from −70 mV to +70 mV, but the concentrations of all ions in the intracellular and extracellular fluids are unchanged. Predict how this change in membrane potential affects the movement of Na+. The electrical gradient for Na+ would tend to move Na+ __________ while the chemical gradient for Na+ would tend to move Na+ __________.

Answer 1

Answer: The correct answer is 1. outside and 2. inside.

Explanation:

During the resting potential (-70 mV), the concentration of Na+ is bigger outside than inside, so this situation generates a trend for moving inside. If we consider a scenario where the resting potential changes from -70 mV to +70 mV, we would realize that the electrical gradient would stop the entrance of Na+ ions and would make them to move outside.