Membránpotenciáljában

Membránpotenciáljában refers to the electrical potential difference that exists across the plasma membrane of all living cells. This potential difference is primarily established by the uneven distribution of ions, such as sodium (Na+), potassium (K+), chloride (Cl-), and large negatively charged organic molecules, inside and outside the cell. The cell membrane is selectively permeable, meaning it allows some ions to pass through more easily than others. This selective permeability, combined with the action of ion pumps like the sodium-potassium pump, which actively transports ions against their concentration gradients, creates and maintains the resting membrane potential.

The resting membrane potential is typically negative inside the cell relative to the outside. This negativity is due to a higher concentration of potassium ions inside the cell and a greater permeability to potassium at rest. However, the influx of sodium ions contributes to depolarizing the membrane. Changes in membrane potential are fundamental to cellular processes, particularly in excitable cells like neurons and muscle cells. Depolarization and repolarization of the membrane underlie the generation and propagation of electrical signals, such as action potentials. These electrical signals are crucial for nerve impulse transmission, muscle contraction, and various other physiological functions. The precise value and dynamics of the membrane potential are tightly regulated to ensure proper cellular activity.