Describe the synaptic transmission of a nerve impulse at the neuromuscular junction

As an action potential arrives at the presynaptic terminal, a depolarisation of the motor neuron membrane occurs which initiates the opening of voltage-gated Ca2+ ion channels - releasing Ca2+ into the neuron to stimulate the release of vesicles containing Acetylcholine. Acetylcholine acts as the neurotransmitter in this context. These vesicles can then bind, and dock to the membrane of the presynaptic neuron with the assistance of SNARE proteins, releasing Acetylcholine into the synaptic cleft. Acetylcholine is then able to diffuse across the synaptic cleft, eventually binding to nicotinic Acetylcholine receptors on the motor end-plate (the post-synaptic membrane). This binding causes a further opening of voltage-gated Na+ ion channels, which cause an influx of Na+, depolarising the membrane. An action potential is then able to be propagated along the sarcolemma as furhter Na+ ion channels are opened.

AB
Answered by Adam B. Biology tutor

7724 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

How do I answer a 'Describe and Explain' question?


What is the structure of DNA?


DNA mismatch repair enzymes repair mainly bases on the newly synthesised DNA strand, using the old DNA strand as a template. If the mismatches were simply repaired without regard for which strand served as template, would this reduce replication errors ?


What happens during eutrophication?


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:

© 2026 by IXL Learning