When potassium ion channels open, which of the following occurs?
A) Potassium ions flow into the axon cytoplasm.
B) The axon cytoplasm becomes more negatively charged.
C) Sodium ions diffuse into the axon cytoplasm.
D) The threshold potential is reached.
E) More sodium channels open.

Question

Quizplus · Accepted Answer

When potassium ion channels open, potassium ions flow out of the axon cytoplasm, not into it. This outflow of positively charged potassium ions makes the inside of the axon more negatively charged relative to the outside, leading to hyperpolarization or a return to the resting membrane potential after an action potential. This process does not involve the inflow of sodium ions, reaching the threshold potential, or the opening of more sodium channels.

When Potassium Ion Channels Open, Which of the Following Occurs