Question

Physiology of the nerve impulses: What condition triggers the opening of voltage-gated Na+ channels during the rising phase? a) Hyperpolarization

b) Threshold potential reached by the membrane voltage
c) Repolarization
d) Resting membrane potential

Answer 1

The opening of voltage-gated Na+ channels during the rising phase of an action potential occurs when the membrane potential reaches the threshold potential.

Step-by-step explanation:

The condition that triggers the opening of voltage-gated Na+ channels during the rising phase of an action potential is b) Threshold potential reached by the membrane voltage. When the membrane potential reaches a certain threshold, typically around -55 millivolts, these channels open and allow an influx of Na+ ions into the neuron. This causes further depolarization, leading to the rising phase of the action potential where the membrane potential swiftly changes from negative to positive.