The resting membrane potential is the relatively stable, ground value of transmembrane voltage in animal and plant cells. It is the electrical potential difference across the plasma membrane when the cell is in a non-excited state. This potential is primarily determined by the movement of ions across the membrane, particularly potassium ions, and the membranes permeability to each type of ion. The resting membrane potential is not an equilibrium potential, as it relies on the constant expenditure of energy for its maintenance. It is generated by the combination of the sodium and potassium pump and the leak channels of these ions. The movement of several different ion species through various ion channels and transporters in the plasma membrane results in different electrostatic charges across the cell membrane, contributing to the establishment of the resting membrane potential.
In summary, the resting membrane potential is a crucial concept in understanding the electrical properties of cells, particularly neurons and muscle cells, and it plays a fundamental role in the physiology of excitable cells.
