Which description best describes the mechanism by which local anesthetic drugs work?
A) Anesthetic drugs bind to the sodium channels,the influx of sodium is interrupted,the action potential cannot rise,and the signal conduction is inhibited.
B) Anesthetic drugs bind to the potassium channels,the influx of sodium is interrupted,the action potential cannot rise,and the signal conduction is inhibited.
C) Anesthetic drugs bind to the sodium channels,the influx of potassium is interrupted,the action potential cannot rise,and the signal conduction is inhibited.
D) Anesthetic drugs bind to the sodium channels,the influx of sodium and potassium is interrupted,the action potential cannot rise,and the signal conduction is inhibited.

Question

Quizplus · Accepted Answer

Local anesthetic drugs bind to the sodium channels, blocking the influx of sodium ions, preventing the depolarization of the neuron, and inhibiting the propagation of nerve signals. This prevents the transmission of pain signals, causing numbness or loss of sensation. Blocking the potassium channels would actually increase the excitability of the neuron, making it more difficult to inhibit the propagation of nerve signals. Blocking both sodium and potassium channels would be overly inhibitory and could lead to muscle paralysis or respiratory depression.

Which Description Best Describes the Mechanism by Which Local Anesthetic