MYTUTOR SUBJECT ANSWERS

256 views

How does acetylcholine transmit the nervous impulse across a synapse?

An action potential from the axon arrives at the presynaptic neuron, stimulating voltage-gated calcium (Ca2+) ion channels to open. This allows calcium ions to diffuse into the synaptic knob, causing synaptic vesicles containing acetylcholine (the neurotransmitter) to fuse with the presynaptic membrane and release into the synaptic cleft: exocytosis. Acetylcholine then diffuses across the synaptic cleft and binds to cholinergic receptors on the postsynaptic membrane, causing ligand-gated sodium (Na+) channels to open. This results in the facilitated diffusion of sodium into the postsynaptic membrane - causing an action potential if threshold is reached. Acetylcholinesterase then breaks down the neurotransmitter to prevent continuous stimulation. 

Charlotte C. A Level Biology tutor

6 months ago

Answered by Charlotte, an A Level Biology tutor with MyTutor


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

175 SUBJECT SPECIALISTS

£26 /hr

Sohini C.

Degree: Medicine,MBBCh (Bachelors) - Cardiff University

Subjects offered:Biology, Science+ 3 more

Biology
Science
Maths
-Personal Statements-
-Medical School Preparation-

“Hi, I'm Sohini. I'm a fourth year medical student at Cardiff uni and keen to help students with Science and Maths GCSE subjects. I can also help with medical school applications, especially personal statements and interviews. ”

£22 /hr

Josh M.

Degree: Biological Natural Sciences (Bachelors) - Cambridge University

Subjects offered:Biology, Physics+ 3 more

Biology
Physics
Maths
Chemistry
-Oxbridge Preparation-

“Who am I? I'm currently studying Natural Sciences in my third year at Cambridge University, with a focus on Neuroscience. Science is my passion, I've loved it at every level I've studied it, and a desire to pass on my passion is part ...”

£22 /hr

Naomi S.

Degree: Medicine (Bachelors) - Trinity College Dublin University

Subjects offered:Biology, Music+ 4 more

Biology
Music
Maths
Human Biology
Chemistry
-Medical School Preparation-

“*Available to teach exam revision sessions immediately.* I'm a medical student at Trinity College Dublin. ”

About the author

£20 /hr

Charlotte C.

Degree: Biological Sciences (Masters) - Durham University

Subjects offered:Biology

Biology

“Hi! If you're looking at my profile, you're probably finding Biology a bit tricky and just need a hand understanding some of the (admittedly complicated!) parts of the course. You'll be relieved to hear that I was once in your shoes -...”

You may also like...

Posts by Charlotte

How does acetylcholine transmit the nervous impulse across a synapse?

How does the structure of DNA make it an effective carrier of genetic information?

Other A Level Biology questions

How does PCR work?

What is the difference between competitive and non-competitive enzyme inhibition?

What makes DNA molecules so stable?

What is a mutation and what are the consequences of one?

View A Level Biology tutors

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

mtw:mercury1:status:ok