Question

Which of the following statements describes how the inhibition of the action of acetylcholinesterase would affect the event that takes place at the neuromuscular junction?

a) Acetylcholine would bind to postsynaptic cell receptor irreversibly.
b) Acetylcholine would accumulate in the synapse.
c) The presynaptic cell would not release acetylcholine.
d) Acetylcholine would be absorbed by the postsynaptic cell.

Answer 1

The inhibition of acetylcholinesterase at the neuromuscular junction would lead to the accumulation of acetylcholine in the synapse because it would not be degraded, causing prolonged muscle contraction.

Step-by-step explanation:

Inhibiting the action of acetylcholinesterase at the neuromuscular junction affects the event taking place as follows: acetylcholine (ACh) would accumulate in the synapse. Without acetylcholinesterase to degrade ACh, it would continually bind and unbind to receptors on the postsynaptic neuron, leading to prolonged muscle contraction. This is because acetylcholinesterase's key role is to clear ACh from the synaptic cleft, allowing the postsynaptic membrane to reset and be ready to receive another signal.

Without this enzyme function, the postsynaptic neuron remains in a state of depolarization due to the continued presence of ACh, which can lead to continuous muscle excitation and contraction. Therefore, the correct answer to the given options is b) Acetylcholine would accumulate in the synapse.