What happens when a resting neuron's membrane depolarizes?
A) There is a net diffusion of Na⁺ out of the cell.
B) The equilibrium potential for K⁺ (EK) becomes more positive.
C) The neuron's membrane voltage becomes more positive.
D) The neuron is less likely to generate an action potential.
E) The cell's inside is more negative than the outside.

Question

Quizplus · Accepted Answer

When a resting neuron's membrane depolarizes, the neuron's membrane voltage becomes more positive. This occurs when there is an influx of positively charged ions, such as Na⁺, into the cell, bringing the membrane potential closer to the threshold for generating an action potential.

Answer: D
 While depolarization makes the neuron more likely to generate an action potential, it does not make it less likely. Therefore, choice D is incorrect.

Answer: A and B 
 Both A and B are incorrect statements. Depolarization involves a net diffusion of positively charged ions, such as Na⁺, into the cell, rather than out of the cell (choice A). Additionally, as the membrane depolarizes, the equilibrium potential for K⁺ becomes more negative, not more positive (choice B).

What Happens When a Resting Neuron's Membrane Depolarizes