Describe an action potential.

A stimulus excites a neuron by causing the opening of sodium channels.
This causes an influx of sodium which causes the opening of other voltage-gated sodium channels.
This causes the membrane to depolarise to threshold. 
Depolarisation is followed by hyperpolarisation where potassium ions leave the cell. 
This returns the membrane to resting potential. 

MK
Answered by Maciek K. Biology tutor

5593 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Using mendelian genetics, explain how two brown eyed parents can have a blue eyed child. Which of the alleles is dominant? You may use a graph to support your explanation (Tip: Assume a simple dominance and inheritance )


What role does the heart play in the circulation of blood around the body?


How does genetic engineering work?


How is information contained in the nuclear DNA of a cell converted into proteins? Outline the role of each molecule and enzyme involved in the process.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning