Final answer:
Lidocaine blocks voltage-gated sodium channels, disrupting pain signal transmission and causing numbness.
Step-by-step explanation:
Lidocaine, a local anesthetic, works by blocking voltage-gated sodium channels. This blockage prevents the movement of sodium ions across the neuronal membrane, which is necessary for generating action potentials. By blocking these channels, lidocaine disrupts the transmission of pain signals, leading to numbness and pain relief.