Question

What would prevent the binding of ACh with ACh-receptor membrane channels on the motor end plate, resulting in no action potential and muscle contraction?

1) Lack of calcium ions in the sarcoplasm
2) Excessive release of ACh from the motor neuron
3) Blockage of ACh-receptor membrane channels
4) Increased permeability of the sarcolemma

Answer 1

Blockage of ACh-receptor membrane channels would prevent ACh from binding to the motor end plate, hindering action potential and muscle contraction. This scenario is seen in conditions such as myasthenia gravis.

Step-by-step explanation:

One factor that would prevent the binding of acetylcholine (ACh) with ACh-receptor membrane channels on the motor end plate, resulting in no action potential and muscle contraction, is blockage of ACh-receptor membrane channels. This can occur in conditions like myasthenia gravis, where the ACh receptors are impaired. Botulinum toxin also inhibits muscle contraction by preventing the release of ACh from the motor neuron, highlighting another potential interference point in the process of muscle contraction.