Which term denotes the brief wave of electrical activity that propagates along a neuron?

Which term denotes the brief wave of electrical activity that propagates along a neuron?

• A. Resting potential
• B. Action potential
• C. Threshold
• D. Aphasia

Answer: (B)

The term for the brief wave of electrical activity that propagates along a neuron is the action potential. This signal starts when excitatory inputs depolarize the membrane to the threshold, triggering voltage-gated sodium channels to open. Sodium ions rush in, causing a rapid spike in membrane potential (depolarization) that travels along the axon as adjacent segments reach threshold and fire in sequence. Because this is an all-or-none event, the strength of the signal remains consistent as it moves. After the peak, potassium channels open to restore the negative membrane potential (repolarization), with a brief hyperpolarization before returning to the resting state. The resting potential is simply the baseline electrical state of the neuron, not a propagating event, and the threshold is the level of depolarization needed to trigger the spike. Aphasia is unrelated to this electrical process. In myelinated axons, conduction speeds up via saltatory conduction, where the action potential effectively jumps between gaps in the myelin.

The term for the brief wave of electrical activity that propagates along a neuron is the action potential. This signal starts when excitatory inputs depolarize the membrane to the threshold, triggering voltage-gated sodium channels to open. Sodium ions rush in, causing a rapid spike in membrane potential (depolarization) that travels along the axon as adjacent segments reach threshold and fire in sequence. Because this is an all-or-none event, the strength of the signal remains consistent as it moves. After the peak, potassium channels open to restore the negative membrane potential (repolarization), with a brief hyperpolarization before returning to the resting state. The resting potential is simply the baseline electrical state of the neuron, not a propagating event, and the threshold is the level of depolarization needed to trigger the spike. Aphasia is unrelated to this electrical process. In myelinated axons, conduction speeds up via saltatory conduction, where the action potential effectively jumps between gaps in the myelin.