I have to make a diagram of a neuron and label the given parts. I have it all finished except for sodium and potassium. I asked my teacher and he said they go in the action potential. I am not sure which one goes where though. I think the sodium is outside and the potassium is inside but then something changes in the action potential right?
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This is a nice animation, and short quiz. Sodium and potassium are both inside and outside, but in different amounts.
You're correct that both sodium and potassium play important roles in the action potential of a neuron. To help you understand their locations and their changes during an action potential, let's break it down.
In a resting neuron, there is a higher concentration of sodium ions (Na+) outside the cell and a higher concentration of potassium ions (K+) inside the cell. This is maintained by the sodium-potassium pump, which actively transports sodium out of the cell and potassium into the cell, against their concentration gradients.
During an action potential, the neuron undergoes a rapid change in membrane potential. It starts with a depolarization phase, where sodium channels on the cell membrane open up, allowing sodium ions to rush into the cell. This sudden influx of positively charged sodium ions results in a rapid increase in the cell's membrane potential, making it more positive.
As the membrane potential approaches its peak, the sodium channels close, and potassium channels open. This begins the repolarization phase, where potassium ions start to exit the cell, moving from inside to outside. The efflux of positively charged potassium ions leads to the re-establishment of the cell's resting membrane potential, making it more negative again.
So, to summarize, during the action potential, sodium ions (Na+) briefly move from outside the cell to inside the cell during depolarization, while potassium ions (K+) move from inside the cell to outside the cell during repolarization.
When labeling your neuron diagram, you can denote the direction of sodium and potassium ion movement during the action potential by showing sodium moving inside the cell during depolarization, and potassium moving outside the cell during repolarization.