Describe the events that take place in a neurone which produce an action potential

  • The action potential begins when the stimulus exceeds the threshold.
    - The voltage gated sodium ion channels open.
    - Sodium ions diffuse into the axon down an electrochemical gradient.
    - Positive feedback occurs (more sodium ion channels open).
    - This depolarises the membrane.
    - The membrane potential reverses from -65mV to +40mV.
    - The voltage gated potassium ion channels now open.
    - Potassium ions diffuse out of the axon down an electrochemical gradient.
    - The sodium ion channels close.
    - Hyperpolarisation occurs.
    - But the sodium potassium pump then restores the resting potential by actively transporting 3 Na+ out of the axon and 2K+ into the axon.
LG
Answered by Lauren G. Biology tutor

11723 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Name the first stage of mitosis, and describe what happens at this stage


What does it mean if genes are linked?


How does a vaccine lead to the production of antibodies and why does this provide immunity?


What is the difference beween biological species concept and the phylogentic approach to defining species?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences