• The junction between two neurones is known as a?synapse

A synapse

• Neurones never touch each other
• The junctions (gaps) in between them are called?synapses
• The electrical impulse travels along the first axon
• This triggers the nerve-ending of the presynaptic neurone to release?chemical?messengers called?neurotransmitters?from vesicles which fuse with the presynaptic membrane
• The neurotransmitters?diffuse?across the synaptic gap (or cleft) and?bind with receptor molecules?on the membrane of the second neurone (known as the?postsynaptic?membrane)
• This?stimulates?the second neurone to generate an electrical impulse that travels down the second axon
• The neurotransmitters are then?destroyed to prevent continued stimulation?of the second neurone which would cause repeated impulses to be sent
• Synapses ensure that impulses?only travel in one direction, avoiding confusion within the nervous system if impulses were travelling in both directions
• As this is the only part of the nervous system where messages are?chemical?as opposed to electrical, it is the?only place where drugs can act to affect the nervous system?- eg. this is where heroin works

How an impulse is passed on at a synapse