What would be most strongly affected by a drug that inhibited the opening of vol

Question

What would be most strongly affected by a drug that inhibited the opening of voltage-gated potassium channels (also known as delayed rectifiers)?

A. Falling phase of an action potential

B. Rising phase of an action potential

C. Resting membrane potential

D. Threshold for an action potential

Why does the voltage during the undershoot phase of the action potential become more negative than the resting membrane potential?

A. During the undershoot potassium ions are flowing into the cell due to the reversal of the potassium concentration gradient occurring during the action potential

B. The undershoot phase results from a delay in the activation of sodium channels, resulting in some sodium channels being open after the voltage-gated potassium channels have closed. C. The potassium conductance is higher during the undershoot than during the resting membrane potential.

D. The concentration gradient for potassium has been reversed as a result of the action potential, and the undershoot phase lasts until this the concentration gradient is restored.

Explanation / Answer

ANS 1) D) Threshold  for an action potential.

because voltage-gated ion channels play a essential function within the era and propagation of the cardiac movement ability via acting synergistically to produce an ionic contemporary across cellular membranes. Therefore, when due to effect of drug that inhibits the opening of voltage-gated potassium channels the overall that is Threshold  for an action potential is affected.

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ANS 2) B) The undershoot phase results from a delay in the activation of sodium channels, resulting in some sodium channels being open after the voltage-gated potassium channels have closed.

because during single motion potentials, transient depolarization of the membrane opens more voltage-gated okay channels than are open within the resting kingdom, many of which do now not close right away while the membrane returns to its regular resting voltage. this will lead to an "undershoot" of the membrane capability to values which can be negative

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