Some poisons work by interfering with synaptic transmission at a neuromuscular junction. Describe the events at a synapse which lead to an action potential.

Across a membrane, there is a voltage at rest and this is known as the resting potential. This is deermined by the membrane permeability to different ions ie which ion channels are open at rest, and also by the sodium potassium pump, which actively maintains a sodium gradient. The arrival of an impulse causes ion channels to open, and the flow of ions causes the membrane potenial to change- this is depolarisation. This depolarisation leads to the formation of an action potential, and this passes along the post synaptic axon, thus generating a nerve impulse