MYTUTOR SUBJECT ANSWERS

242 views

What occurs during an action potential in a neuron?

At rest, the potential difference between the inside and outside of the neuron is around -70mV. The sodium potassium pump is continually pumping 3 Na+ ions out for every 2 K+ ions it pumps in, and this maintains the resting potential of -70mV. 

During an action potential a few sodium ion channels open, and Na+ diffuses into the neuron, decreasing the value of the potential difference. If and when the potential difference reaches the threshold potential of -50mV voltage-gated sodium ion channels open and the neurone is depolarised reaching a maximum potential difference of +40mV. 

At this point the sodium ion channels close and potassium ion channels open allowing K+ ions to diffuse out of the neuron which is repolarised to -70mV. Generally this target is overshot (hyperpolarisation) to about -90mV, but the sodium-potassium pump corrects this. 

Sophie C. GCSE Biology tutor, A Level Biology tutor, GCSE Chemistry t...

10 months ago

Answered by Sophie, an A Level Biology tutor with MyTutor

Still stuck? Get one-to-one help from a personally interviewed subject specialist

132 SUBJECT SPECIALISTS

£20 /hr

Ollie F.

Degree: Biochemistry (Bachelors) - Bristol University

Subjects offered: Biology, Science+ 5 more

Biology
Science
Physics
Maths
Extended Project Qualification
Chemistry
-Personal Statements-

“A little bit about me: I'm a Biochemistry student at Bristol University. I've always been facinated with how the world world works both on a smaller and larger scale. The human body has always been an interest of mine, in particular h...”

£20 /hr

Amelia A.

Degree: Medicine (Bachelors) - Bristol University

Subjects offered: Biology, Spanish

Biology
Spanish

“About Me: ​​Hello! My name is Amelia. I am a second year Medicine student at the University of Bristol. I offer help with Sciences, in particularBiology. I have always had a passion for languages and I would be delighted to assist an...”

MyTutor guarantee

£20 /hr

Liam P.

Degree: Biological Sciences with integrated masters (Masters) - Durham University

Subjects offered: Biology, Maths

Biology
Maths

“A little bit about me I am currently studying for my masters in Biology at the University of Durham. In the coming year I will be working on modelling the effect of climate change on migratory birds. I found studying bird migration fa...”

MyTutor guarantee

About the author

Sophie C.

Currently unavailable: for regular students

Degree: Biology (Bachelors) - Bristol University

Subjects offered: Biology, Maths+ 2 more

Biology
Maths
Geography
Chemistry

“About Me: I'm currently in my first year studying Biology at Bristol University. I'm enthusiastic about my subject and science in general and would love to help others to love it as much as I do!  My Experience: I have experience me...”

You may also like...

Posts by Sophie

What occurs at a constructive plate margin?

What occurs during an action potential in a neuron?

Other A Level Biology questions

How does PCR work?

What are the stages of mitosis?

What is respiration and why is it needed?

What are the key steps in the light dependent reaction of photosynthesis?

View A Level Biology tutors

Cookies:

We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok