| A | B |
|---|
| stimulation | some sodium ions leak into the cell |
| depolarisation | sodium channels open and sodium ions diffuse rapidly into the cell |
| repolarisation | potassium channels open and potassium ions diffuse out of cell |
| hyperpolarisation | membrane potential drops below resting potential as there is a delay in closing potassium channels |
| refractory period | neurone cannot respond |
| resting potential | potential difference across membrane when no impulse is passing - always negative |
| threshold potential | increase in membrane potential needed to fire an action potential |
| nerve impulse that travels along axon | action potential |
