synaptic transmission

Question 1

synapse

Answer 1

A specialised gap between neurons through which the electrical impulse from the neuron is transmitted chemically.

Question 2

process

Answer 2

When the electrical signal reaches the axon terminal of a neutron, it prompts the release of neurotransmitters from vesicles.
The neurotransmitters diffuse across the synapse and bind to receptors on the post-synaptic cell.
The chemical message is then converted back into an electrical impulse.

Question 3

excitation

Answer 3

When a neurotransmitter, such as adrenaline, increases the positive charge of the postsynaptic neuron. Makes the postsynaptic neurone more likely to fire and pass on the electrical impulse.
Acts as the nervous systems’ “on switches”.

Question 4

inhibition

Answer 4

When a neurotransmitter, such as serotonin, increases the negative charge of the postsynaptic neuron. Makes the postsynaptic neuron less likely to fire and pass on the electrical impulse.
Acts as the nervous systems’ “off switches”.

Question 5

summation

Answer 5

Whether the postsynaptic neuron fires is decided by summation - the excitatory and inhibitory influences are summed.
If inhibitory inputs are higher than excitatory inputs, they can cancel out excitation and inhibit an action potential occurring - the neuron will be less likely to ‘fire’.
If excitatory inputs are higher than inhibitory inputs, they can cancel out inhibition and excite an action potential - the neuron will be more likely to ‘fire’.