Final answer:
The opening of sodium channels during an action potential is caused by the binding of sodium ions.
The opening of sodium channels during an action potential is caused by the depolarization of the membrane, which happens when the voltage across the cell membrane becomes more positive.
Step-by-step explanation:
The opening of sodium channels during an action potential is caused by the binding of sodium ions. When the membrane depolarizes, voltage-gated sodium channels are triggered to open, allowing sodium ions to enter the cell. This influx of positive charge initiates the action potential.
The opening of sodium channels during an action potential is caused by the depolarization of the membrane, which happens when the voltage across the cell membrane becomes more positive.
When sodium channels open during an action potential, the opening is caused by depolarization of the membrane, which is a shift from the resting potential. Depolarization is a process that occurs when the inside of a neuron becomes less negative compared to the outside. This is triggered by a change in voltage across the neuron's cell membrane, specifically when the membrane potential becomes more positive. The opening of these channels allows sodium ions (Na+) to rush into the neuron, further depolarizing the membrane and propagating the action potential along the axon.
The action potential is an all-or-nothing event that begins when the neuron's membrane potential reaches a certain threshold of excitation. The depolarization of the membrane proceeds in a wave down the length of the axon, moving in only one direction due to the inactivation of the sodium channels immediately after opening, preventing a reverse-flow of the signal.