Synapses

• Neurones must pass impulses to each other in order to send messages. But they do not actually touch.
• The place where two neurones meet is called a synapse. There is a tiny gap at the end of the first neurone and the start of the second neurone.
• At a synapse, an electrical impulse causes a chemical to be released into the gap. This chemical diffuses to the next neurone and causes an electrical impulse.
• In the nerve ending of the first neurone there are hundreds of tiny vesicles which contain a chemical called a neurotransmitter.
• When an impulse reaches the nerve ending, vesicles fuse with the cell membrane and empty the neurotransmitter into the gap.
• The transmitter substance diffuses across the gap and slots into a receptor on the dendrite of the next neurone. This triggers an electrical impulse in the next neurone.
• What is a synapse? 


  A place where two or more neurones meet.