Structure of a synapse and action potentials

Question 1

Outline the process of axon potential when a neurone sends information down the axon

Answer 1

1. A stimulus first causes sodium channels to open. Because there are so many more sodium ions on the outside, and the inside of the neuron is relatively negative to the outside, sodium ions rush into the neuron.
2. Sodium has a positive charge so the neuron becomes more positive and becomes depolarised
3. It takes longer for the potassium channels to open and when they do potassium rushes out of the cell, reversing the depolarisation. Also round this time sodium channels being to close
4. This causes action potential to go back toward -70mV (a repolarisation). The action potential actually goes past -70mV (a hyper-polarisation) because the potassium channels stay open too long.
   Gradually the ion concentrations go back to resting levels and the call returns to -70mV cell body