REVIEW - Membrane Potentials and Action Potentials

This set of flashcards covers key concepts related to the resting membrane potential, depolarization, repolarization, hyperpolarization, and the function of the Na⁺/K⁺ pump in neurons.

What is the resting membrane potential of a neuron?

About -70 mV (inside more negative than outside).

Which ions are most responsible for depolarization?

Sodium (Na⁺) entering the cell.

Which ions are most responsible for repolarization?

Potassium (K⁺) leaving the cell.

What happens if K⁺ channels stay open too long?

The cell hyperpolarizes (becomes too negative).

What restores the resting potential after an action potential?

The sodium-potassium pump.

What happens to the inside of the neuron during depolarization?

It becomes less negative (more positive).

What happens during hyperpolarization?

The inside becomes more negative than the resting potential.

Which ion movement makes the inside of the neuron more negative?

K⁺ leaving or Cl⁻ entering.

What triggers voltage-gated Na⁺ channels to open?

A stimulus that depolarizes the membrane to threshold (~ -55 mV).

What is the function of the Na⁺/K⁺ pump?

To maintain resting potential by pumping 3 Na⁺ out and 2 K⁺ in.