Synapses

• Neurones must pass impulses to each other in order to send messages. They don't actually touch though.
• Where two neurones meet is called a synapse.
• At a synapse, an electrical impulse causes a chemical to be released into the gap. The 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 transmitter substance (also called a neurotransmitter)
• When an impulse reaches the nerve, the vesicles fuse with the cell membrane and empty the neurotransmitter into the gap.
• The neurotransmitter diffuses across the gap and slots into a receptor on the dendrite (branch ending) of the next neurone. This triggers an electrical impulse in the next neurone