An autoimmune disease targets myelin sheaths in the nervous system. Which effect dominates as demyelination progresses?

💡 Explanation

Demyelination impairs saltatory conduction, which relies on myelin sheaths to speed action potential propagation. Because myelin acts as an insulator, its loss reduces conduction velocity. Therefore, action potential velocity diminishes, rather than increasing as in option B, or affecting neurotransmitter activity as in options A and C.

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