10.7 Transmission across a Synapse

Step 1: Calcium ion channels are caused to open on the synaptic knob as the action potential arrives. There is an influx of calcium ions into the synaptic knob.

Step 2: Synaptic vesicles containing acetylcholine are released into the synaptic cleft as the vesicles attach to the presynaptic membrane.

Step 3: The acetylcholine binds with receptor site on sodium channels on the the post-synaptic neurone causing them to open, allowing sodium to flow down a concentration gradient into the post-synaptic neurone.

Step 4: This generates the action potential in the post-synaptic neurone.

Step 5: The acetylcholine then leaves the receptor…