Synaptic transmission Flashcards
Synaptic transmission
Process for transmitting messages from 1 neuron to the next
Electrical impulse from the neuron is carried by chemicals through the synapse to the next neuron
Process of synaptic transmission
Electrical impulse travels down axon in the pre-synaptic neuron,
Vesicles at end of axon contain neurotransmitters, when the electrical impulse reaches the vesicle, it causes them to release their contents across the synapse
Neurotransmitters then diffuse across the synapse
In the adjacent neuron, neurotransmitters bind to the receptors and are then converted back into electrical impulses to travel down the next neuron
Excitatory neurotransmitter
Nervous systems ‘on switches’ and they increase the likelihood of the post-synaptic neuron firing
Inhibitory neurotransmitters
Nervous system ‘off switches’ and they decrease the likelihood of the neuron firing
Summation
A neuron firing depends on summation
If the sum of the neurotransmitters entering the post-synaptic neuron are excitatory the neuron will fire
If the sum of the neurotransmitters entering are inhibitory, the neuron will be less likely to fire
Dendrites
Carry nerve impulses from neighbouring neurons towards cell body
Cell body
Includes a nucleus
Nucleus
Inside cell body, contains genetic material
Axon
Carries electrical impulse away from cell body down length of neuron
Myelin sheath
Fatty layer that protects and insulates axon
Nodes of ranvier
Gaps in axon that speed up transmission of impulse
Axon terminal
Where nerve impulses pass from one nerve to another by crossing synaptic gap
