Explain the process of synaptic transmission

An action potential reaches the presynaptic neurone. This causes calcium channels to open, leading to calcium ions entering the synaptic knob via facilitated diffusion. This causes synaptic vesicles containing acetylcholine to fuse with the presynaptic membrane, which then causes acetylcholine to be released into the synaptic cleft. The acetlycholine molecules diffuse across the synaptic cleft and bind to sodium receptor channels in the postsynaptic membrane. This causes an influx of sodium ions into the postsynaptic membrane, causing the generation of an action potential.Acetylcholinesterase hydrolyses the acetylcholine rapidly, to prevent further generation of action potentials. ATP from mitochondria recombines choline and ethanoic acid back into acetylcholine. The sodium ion channels close in the absence of acetylcholine.