How are impulses propagated along an axon?

The axon is polarised at rest. This means that there is a negative charge within the axon and a positive charge outside. This resting polarisation is caused by a Na/K pump that uses active transport to transport 3 Na+ ions out of the axon in exchange for two K+ ions entering the axon. This means that more positive ions are outside the axon causing an electrochemical gradient. When an impulse is generated, the change in charge causes Na+ voltage gated channels to open and Na+ ions to rush into the axon down their electrochemical gradient. This means the once polarised axon becomes depolarised and this is an action potential. This change in charge in this section of the axon causes voltage gated Na+ channels to open on the next section of the axon and this whole process begins again. This happens in a domino-like fashion so that an action potential propagates itself along an axon.

ZF
Answered by Zia F. Biology tutor

5447 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Explain the process of DNA replication an state why it is called semi-conservative.


How does the body respond following a meal to ensure a relatively constant blood sugar level?


Use your knowledge of Water Potential applied to the GIT to describe what can cause or prevent Constipation


How does adrenaline, using the second messenger model, cause glycogenolysis?


We're here to help

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

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences