Which of the following best describes how a neuron fires?

Question

Quizplus · Accepted Answer

When a neuron fires, an action potential (electrical signal) is initiated by the movement of Na+ ions into the cell and K+ ions out of the cell through ion channels in the plasma membrane. This creates a wave-like depolarization that travels down the axon. The sequence of events is often abbreviated as Na⁺, which stands for the opening of voltage-gated sodium channels (S1), followed by the influx of Na+ ions (U1) and the depolarization of the membrane potential to +1 mV (P1), then the closing of voltage-gated sodium channels (S1) and the opening of voltage-gated potassium channels (S1) that allow K+ ions to leave the cell and repolarize the membrane potential to -70 mV (P0). This process repeats along the length of the axon, resulting in the propagation of the action potential to other neurons or muscles. Vesicles and neurotransmitters are involved in the release of chemical signals at synapses, but they do not initiate the firing of neurons.

Which of the Following Best Describes How a Neuron Fires