FL #1, bio #3

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birdyann
Posts: 1
Joined: Tue Feb 18, 2020 4:13 pm

FL #1, bio #3

Post by birdyann » Tue Feb 18, 2020 4:20 pm

Hi!

For this question, it asks: "Which of the following processes is involved in the motor-evoked potential elicited by transcranial magnetic stimulation?" I assumed it was just referring to the potential of the muscle since in the passage it says: "Transcranial magnetic stimulation (TMS) of the motor cortex uses a powerful, focused magnetic field to depolarize brain neurons and elicit motor-evoked potentials (MEPs) from the skeletal muscle." Which to me implies that MEPs are specific to the skeletal muscle and separate from the neuron depolarization. So I thought only RN II was true. Can someone explain what all the MEPs include?

Thank you!
NS_Tutor_Mathias
Posts: 543
Joined: Sat Mar 30, 2019 8:39 pm

Re: FL #1, bio #3

Post by NS_Tutor_Mathias » Mon Mar 09, 2020 5:16 pm

You are correct that the MEP itself refers to the action of the muscle.

The neuromuscular junction however also works by an initial influx of sodium, so this would however not change the answer. The question stem also asks about what is 'involved in', implying that the physiology of the entire neural conduction pathway may be involved.

In my opinion, the phrasing should be narrowed to solely the action on the myocyte. The answer however would remain identical.
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