Question

Events that occur at a cholinergic synapse are listed here, but they are arranged in an incorrect order. Choose the correct order of these events below.

(a) Calcium influx triggers exocytosis of ACh.
(b) An action potential depolarizes the synaptic terminal.
(c) ACh is removed by AChE.
(d) ACh binds to receptors on the postsynaptic membrane

Answer 1

The correct order of events at a cholinergic synapse is: depolarization of the synaptic terminal, calcium influx triggering exocytosis of ACh, ACh binding to receptors on the postsynaptic membrane, and removal of ACh by AChE.

Step-by-step explanation:

The correct order of events at a cholinergic synapse is:

1. An action potential depolarizes the synaptic terminal.
2. Calcium influx triggers exocytosis of ACh.
3. ACh binds to receptors on the postsynaptic membrane.
4. ACh is removed by AChE.

When an action potential reaches the synaptic terminal, it causes depolarization of the membrane, allowing calcium ions to enter the cell. The influx of calcium triggers the release of ACh from synaptic vesicles into the synaptic cleft.

ACh then binds to ACh receptors on the postsynaptic membrane, initiating the transmission of the signal. Finally, ACh is removed from the synaptic cleft by the enzyme AChE to terminate the signal transmission.