Lidocaine, a Use-Dependent Blocker of Voltage-Gated Na⁺ Channels, Is an Effective

question 8

Multiple Choice

Lidocaine, a use-dependent blocker of voltage-gated Na⁺ channels, is an effective antiarrhythmic because its blocking effect becomes greater when:

• A) The drug is repeatedly used.
• B) Na⁺ channels are activated repeatedly at a high frequency.
• C) Na⁺ channels are activated repeatedly at a low frequency.
• D) Na⁺ channels are closed.
• E) The extracellular Na⁺ concentration is high.

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Definitions:

P-waves

Primary waves, or compressional waves, are the fastest seismic waves that travel through solids, liquids, and gases in a push-pull motion.

S-waves

Secondary or shear waves, a type of elastic wave that moves through the body of the Earth, used in the study of earthquakes and the Earth's interior.

Oceanic Trench

Deep, underwater canyons formed by the subduction of one tectonic plate under another at convergent plate boundaries.

Magmatic Belt

A geographic zone that is extensively populated by igneous rocks which have been or are being formed by magmatic processes typically related to tectonic plate boundaries.