SET 28: Resting, Depolarization & Hyperpolarization 🔁 SET 29: Graded vs Action Potentials

What is resting membrane potential?

The charge difference when the neuron is inactive

What is the typical resting value?

About -70 mV

What is depolarization?

A decrease in membrane potential (more positive)

What causes depolarization?

Increased Na+ or Ca2+ entry or decreased K+ movement out

What is hyperpolarization?

An increase in membrane potential (more negative)

What causes hyperpolarization?

Increased K+ leaving or Cl- entering the cell

Why is resting potential important?

It allows neurons to respond to stimuli

What is a graded potential?

A small, local change in membrane potential

What happens to graded potentials over distance?

They decrease in strength

Can graded potentials add together?

Yes, they can summate

What is an action potential?

A large signal that travels across the entire membrane

What triggers an action potential?

Reaching threshold

What is threshold?

The minimum stimulus needed to trigger an action potential

What does all-or-none mean?

The action potential occurs fully or not at all