N92 The resting potential of a myelinated nerve liber is primarily dependent on the concentration gradient of which of the following ions? Ca CI HCO3 K Na

The resting potential of a myelinated nerve fiber is primarily dependent on the concentration gradient of potassium ions (K+). The resting potential is typically around -70 mV, with the inside of the cell being more negative relative to the outside. This is maintained by the sodium-potassium pump, which actively transports 3 Na+ ions out of the cell and 2 K+ ions into the cell, creating a concentration gradient for these ions. The high concentration of K+ inside the cell and Na+ outside the cell leads to a negative charge inside the cell, establishing the resting potential.