The ion distribution that creates the resting membrane potential in an inactive neuron is characterized by a higher concentration of positively charged ions (cations) outside the cell than inside, and a higher concentration of negatively charged ions (anions) inside the cell than outside. This imbalance of ions is maintained by a combination of ion concentration gradients and ion channels in the cell membrane.
Ion concentration gradients
Ion concentration gradients are the result of different concentrations of ions on either side of the cell membrane. The two most important ions for establishing the resting membrane potential are potassium (K+) and sodium (Na+). K+ ions are more concentrated inside the cell than outside, while Na+ ions are more concentrated outside the cell than inside. These concentration gradients are created by active transport pumps, such as the Na+/K+ pump, which use energy to move ions across the cell membrane against their concentration gradient.
Ion channels
Ion channels are proteins embedded in the cell membrane that allow ions to pass through the membrane. There are many different types of ion channels, each of which is selective for a particular ion. The two most important types of ion channels for establishing the resting membrane potential are potassium channels and sodium channels. Potassium channels are more open at rest than sodium channels, which allows K