Question

To ensure that the large volume of ACh released does not initiate more than one EPP:

A) Acetylcholinesterase degrades ACh in the synaptic cleft

B) ACh is rapidly transported back into the motor neuron

C) Calcium ions block ACh receptors on the postsynaptic membrane

D) ACh is released in small, controlled amounts

Answer 1

To prevent multiple EPPs, acetylcholinesterase breaks down acetylcholine in the synaptic cleft, ensuring it cannot repeatedly bind to receptors and cause extended muscle contractions.

Step-by-step explanation:

To ensure that the large volume of acetylcholine (ACh) released does not initiate more than one endplate potential (EPP), the correct answer is: A) Acetylcholinesterase degrades ACh in the synaptic cleft. This crucial enzyme, acetylcholinesterase (AChE), resides within the synaptic cleft and breaks down ACh into acetyl and choline. This rapid degradation prevents ACh from remaining bound to ACh receptors on the motor end plate, which would otherwise lead to prolonged muscle contraction and potential overstimulation of the muscle fiber.