Chapter: 3 Movement in & out of Cells

Synapses

• If you look carefully at figure 12.4, you will see that the three neurons involve in the reflex arc do not quite connect to each other.
• There is a small gap between each pair.
• These gaps are called synaptic gaps .
• The ends of the two neurons on either side of the gap, plus the gap itself, is called a synapse.
• Figure 12.8 shows a synapse between a sensory neurone and a relay neurone in more detail.
• Inside the sensory neurone’s axon are hundreds of tiny vacuoles, or vesicles.
• These each contain huge number of molecules of a chemical called a neurotransmitter.

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