Cholinergic synapse

Question 1

At a cholinergic synapse, what is the neurotransmitter?

Answer 1

acetylcholine

Question 2

cholinergic synapse - stage 1 - depolarisation

Answer 2

an action potential arrives at the presynaptic knob, depolarising the membrane and causes voltage-gated calcium ion channels to open.

Question 3

cholinergic synapse - stage 2- post-depolarisation

Answer 3

The influx of Ca2+ ions cause the synaptic vesicles to fuse with the membrane, releasing the neurotransmitter into the synaptic cleft.

Question 4

cholinergic synapse - stage 3- action potential

Answer 4

The neurotransmitter diffuses and binds receptors on the postsynaptic membrane, causing an action potential

Question 5

cholinergic synapse - stage 4- post-action potential generation

Answer 5

Acetylcholinesterase breaks down acetylcholine in the cleft.

Question 6

cholinergic synapse - stage 5- if the synapse is excretory

Answer 6

The synapses can be excitatory if the neurotransmitter opens Na+ channels or inhibitory if the neurotransmitter opens chloride or potassium channels causing hyperpolarisation.

Question 7

What is the spatial summation?

Answer 7

when action potentials from multiple presynaptic neurones are added together in a post-synaptic neurone

Question 8

What is the temporal summation?

Answer 8

when multiple action potentials from a single presynaptic neurone are added together in a postsynaptic neurone over time.

Question 9

Draw a Cholinergic synapse.

Answer 9