The opening of more and more Na⁺ channels during depolarization

A) is the result of the sodium-potassium exchange pump.
B) is an example of a positive feedback cycle.
C) is possible only if K⁺ channels remain closed.
D) is the cause of the afterpotential.
E) is an example of a negative feedback cycle.

Positive Feedback Cycle

A process where the end products of an action cause more of that action to occur in a feedback loop, amplifying the original action.

Sodium-Potassium Exchange Pump

A membrane-bound enzyme complex that pumps sodium out of cells while pumping potassium into cells, crucial for maintaining cellular concentration and electrical gradients.

Afterpotential

The transient changes in membrane potential that follow an action potential, including hyperpolarization or depolarization phases, affecting neuron's firing rate.