Question

The reasoning I've been given is that high extracellular[K+][K+]increases theEvEvof potassium; therefore, membrane potential increases and the threshold for action potentials is more easily reached. Conversely, high extracellular[Ca2+][Ca2+]increases the accumulated positive charge outside the cell membrane and therefore increases the membrane potential. However, like withK+K+, wouldn't high ECF[Ca2+][Ca2+]also increase itsEvEvand therefore membrane potential of the cell?

Answer 1

High extracellular concentration of K+ can increase the resting membrane potential, making it easier for the threshold for action potentials to be reached. High extracellular concentration of Ca2+ does not directly affect the resting membrane potential, but it can influence the release of neurotransmitters and the contraction of muscles.

Step-by-step explanation:

High extracellular concentration of potassium ions (K+) can increase the resting membrane potential, making it easier for the threshold for action potentials to be reached. This is because potassium ions play a significant role in establishing the resting potential of the cell membrane.

On the other hand, high extracellular concentration of calcium ions (Ca2+) does not directly affect the resting membrane potential, but it can influence the release of neurotransmitters and the contraction of muscles. So, while both high extracellular concentration of K+ and Ca2+ can have an effect on membrane potential and action potentials, the mechanisms are different.