Multiple sclerosis is a disease caused by the loss of the myelin
sheath around the axons. What is the expected effect of losing the
myelin sheath on action potential transmission at the neuromuscular
junction?
a. The action potential from the motor neuron is normally
transmitted across the synaptic cleft and into the nearby muscle
cell, eventually leading to muscle contraction
b. The action potential from the motor neuron is transmitted
across the synaptic cleft and into the nearby muscle cell, but it
fails to propagate within the muscle cell
c. No action potential can be generated in the neuron itself,
therefore no action potential ever reaches the muscle cell
d. The action potential from the motor neuron cannot be
transmitted across the synaptic cleft, therefore the muscle cell
never receives any signal from the neuron
e. The action potential, when triggered in the motor neuron,
weakens as it propagates down the axon, such that no signal ever
reaches the neuromuscular junction