- How is an action potential generated?
- 1) Stimulus causes a change in the potential difference between the inside and outside of the axon
- 2) Stimulus arriving on an axon causes the Na+ ions to flood/diffuse into the axon.
- 3) There is now a higher concentration of Na+ inside the axon compared to the outside the axon.
- 4) They are NOT pumped in - there is no active transport, they diffuse from a higher concentration outside, to a lower concentration inside.
- 5) The potential difference in charge between inside and outside of the axon membrane is now +40mV - threshold has been reduced
- 6) K+ ions channels close
- 7) sodium-potassium pump stops = depolarised (positive charge inside axon)