- Refractory period
- 1) After an action potential has occurred, the sodium channels close and potassium channels open.
- 2) Potassium diffuses out of the axon. This causes the inside of the axon to become more negative again. The membrane is said to be repolarised
- 3) Too much K+ leaves the axon ---> overshoot. The sodium-potassium pump starts again and restores the ionic balance. This is called the refractory period.
- 4) The purpose of the refractory period is to prevent another action potential being generated. This ensures a unidirectional impulse (impulse only travels in long direction) and limits frequency (prevents over stimulation)
- 5) The resting potential is restored ---> -70mV and an action potential can now be generated