Explain the process that occurs in neuromuscular junctions from when the action potential in the pre-synaptic knob to transmission in the next neurone (6 marks).

  1. The action potential in the pre-synaptic neurone causes calcium ion channels to open

  2. This causes calcium ions to diffuse into the neurone, down its concentration gradient

  3. This causes vesicles containing acetylcholine to fuse to the pre-synaptic membrane

  4. Acetylcholine is then released into the synaptic cleft

  5. Acetylcholine diffuses across the cleft and binds to sodium channels on the post-synaptic membrane, opening them

  6. Sodium ions diffuse into the post-synaptic membrane, causing depolarisation and triggering an action potential

  7. Acetylcholinesterase in the synaptic cleft binds to acetylcholine and delivers it back to the pre-synaptic knob to be recycled

HE
Answered by Holly E. Biology tutor

2659 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Describe and explain the effect of an increase in muscular activity on the heart rate.


How are Genes and DNA organised?


How are electron microscopes (TEM) fundamentally different from light microscopes and what are the advantages and disadvantages of each?


How is immunity reached after a vaccine is given? Include the roles of both T cells and B cells.


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:

© 2025 by IXL Learning