How Would Artificially Increasing the Potassium Ion Concentration in the Extracellular Neural Fiber Bath Affect Its Resting Membrane Potential and Action Potential?

Question

If the potassium ion concentration in the bath of isolated neural fibers is artificially increased, how would it change the absolute value of the resting membrane potential and the amplitude of the action potential? What would be the difference in a non-isolated state, such as within the human body?

Answer

According to the Nernst equation, increasing the potassium ion concentration in the extracellular neural fiber bath would result in an increase in the absolute value of the resting membrane potential and also enhance the amplitude of the action potential. However, within the human body, the situation is more complex, as the body would spontaneously adjust to maintain a balance of intracellular and extracellular potassium ion concentrations. If extracellular potassium concentration rises, the body would quickly pump potassium ions into cells through proton pumps to avoid the dangerous condition of high extracellular potassium levels.