Lepopotentiaalia

Lepopotentiaalia, often translated as resting potential, refers to the electrical potential difference across the plasma membrane of a neuron or muscle cell when it is in a non-excited state. This potential is typically negative on the inside relative to the outside. Several factors contribute to the establishment and maintenance of this resting potential. The differential distribution of ions across the cell membrane is a primary cause. Key ions involved include sodium (Na+), potassium (K+), chloride (Cl-), and large negatively charged organic molecules. The sodium-potassium pump plays a crucial role by actively transporting three sodium ions out of the cell for every two potassium ions pumped into the cell, thereby creating and maintaining concentration gradients. The selective permeability of the membrane to these ions, particularly potassium due to leak channels, also contributes significantly to the negative internal charge. As potassium ions diffuse out of the cell down their concentration gradient, they leave behind a net negative charge inside the cell. The resting potential is a fundamental property of excitable cells, serving as the baseline from which electrical signals like action potentials are generated.