1. Nerve Impulses

2. Resting Potentials
Electrical potential across plasma membrane of a cell
Not conducting impulse

3. Action Potentials
Reversal & restoration of electrical potential across the plasma memebrane of a cell
Electrical impulse passes along it

4. Stages in Passage of Nerve Impulse
Diffusion of sodium ions
Local currents reduce resting potential

5. Depolarization
Sodium channels open
Sodium ions diffuse into neuron

6. Repolarization Potassium channels open after short delay
Potassium ions diffuse out of neuron

7. Ion Movements Concentration gradient of Na & K are restored
Restores resting potential
Ready to conduct next nerve impulse

8. Page Number & Vocabulary
Study Guide: p.53
Course Companion: p
HL Pearson: p
Resting Potential: electrical potential across plasma membrane of cell that is not conducting impulse
Action Potential: reversal and restoration of electrical potential across plasma membrane of cell, as electrical impulse passes along it

9. Vocabulary
Depolarization: change in cell’s membrane potential, making more positive
Repolarization: change in membrane potential that returns membrane potential to negative value after depolarization phase of action potential has just previously changed membrane potential to positive value