Which mechanism explains why local anesthetics selectively block pain sensation, rather than all sensory and motor action?

💡 Explanation

Local anesthetics work because they block voltage-gated sodium channels. Small-diameter, unmyelinated C fibers (which transmit pain) are more sensitive to this blockade than larger, myelinated fibers (involved in motor function); therefore, pain is blocked rather than other sensations due to differential nerve fiber sensitivity.

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