Why is the range of action potential taken from 30mV to 45mV?

Introduction: An action potential is an electrical signal that propagates along the membrane of a neuron, resulting in the transmission of information between neurons. It is triggered when the membrane potential of the neuron reaches a certain threshold.

Threshold for Action Potential: The threshold for action potential generation is typically around -55mV to -50mV. However, the actual voltage at which an action potential is generated can vary between neurons and even within a single neuron.

The Range of Action Potential: The range of action potential is typically taken from 30mV to 45mV. This range is used because the amplitude of the action potential is typically around 100mV, and the resting potential of a neuron is around -70mV. Therefore, an action potential that is generated at a voltage below 30mV would be too small to be detected reliably, while an action potential generated above 45mV could potentially damage the neuron.

The Role of Sodium and Potassium: The generation of an action potential is dependent on the flow of ions across the membrane of the neuron, specifically sodium (Na+) and potassium (K+). When the membrane potential reaches the threshold voltage, voltage-gated sodium channels open, allowing Na+ ions to flow into the neuron. This influx of positive charge causes the membrane potential to rapidly depolarize, generating the action potential.

Conclusion: In summary, the range of action potential is typically taken from 30mV to 45mV because this range allows for reliable detection of the signal without causing damage to the neuron. The generation of an action potential is dependent on the flow of ions across the membrane of the neuron, specifically sodium and potassium.