Procaine (Novocain)is a drug that blocks voltage-gated Na⁺ channels. When present,what would happen in a neuron?
A)Graded potentials are possible,but the neuron will not have the depolarizing phase of the action potential.
B)Neither graded potentials nor action potentials will occur.
C)Graded potentials are possible and the neuron will have the depolarizing phase of the action potential,but will be unable to repolarize.
D)No phase of the action potential will be affected.

Question

Procaine (Novocain)is a drug that blocks voltage-gated Na⁺ channels.  When present,what would happen in a neuron?
A)Graded potentials are possible,but the neuron will not have the depolarizing phase of the action potential.
B)Neither graded potentials nor action potentials will occur.
C)Graded potentials are possible and the neuron will have the depolarizing phase of the action potential,but will be unable to repolarize.
D)No phase of the action potential will be affected.

Quizplus · Accepted Answer

Procaine blocks voltage-gated Na⁺ channels, which are essential for the depolarizing phase of the action potential. Graded potentials can still occur because they do not require the opening of these specific channels. However, the neuron will not be able to generate action potentials because the depolarizing phase will not occur.

Procaine (Novocain)is a Drug That Blocks Voltage-Gated Na⁺ Channels