Answer:
Put the following four steps of a cholinergic synapse in their correct order:
1. a. An arriving action potential depolarizes the axon terminal membrane of a presynaptic neuron.
2. c. Depolarization of the axon terminal membrane opens voltage-gated calcium ion channels with the calcium promoting the exocytosis of synaptic vesicles filled with ACh.
3. d. ACh diffuses across the synaptic cleft and binds to receptors on the postsynaptic membrane
4. b. Depolarization of the postsynaptic membrane ends as acetylcholine (ACh) is broken down.
Explanation:
Cholinergic synapses are chemical synapses that that use acetylcholine molecules as the neurotransmitter. When the depolarization occurs, sodium and calcium channels open, and potassium channels close. Then the action potential happens, and then when it comes the repolarization, sodium and potassium channels close.
Answer:
A. C.D, B
Explanation:
The event which initiate cholinergic-acetycholine transmitter- reactions  involves the stimulation of the presynaptic neuron by the action potential, as  synaptic potential This causes the opening of Voltage gated Ca+ channels.
The latter infux  leads to the migration and fusion of the acetycholine contained vesicles to the presynaptic membranes.And eventual empty of the acetycholine into the synaptic cleft by exocytosis.
the acetycholine flows across the cleft to bind with receptors on the post synaptic neuronal membrane.
this causes the opening of Ligand gated  Na+ channels on the post synaptic neuron membrane leading to depolarization. If the this is up to the threshold level, action potential as EPSP .
after a period of time the acetycholine is broken down, by enzyme -acetylcholinesterase, so that fatigue of neuron is prevented,and continuous availability of acetycholine is ensured.
