Cellepotentiale

Cellepotentiale, also known as membrane potential, refers to the difference in electrical potential between the interior and exterior of a biological cell. This potential difference is established and maintained by the selective permeability of the cell membrane to ions and the action of ion pumps. Typically, the inside of a cell is negatively charged relative to the outside, creating a resting membrane potential. This resting potential is crucial for various cellular functions, including nerve impulse transmission, muscle contraction, and nutrient transport.

The resting membrane potential is primarily determined by the concentration gradients of ions such as sodium (Na+), potassium (K+), chloride (Cl-), and calcium (Ca2+), and the relative permeability of the membrane to these ions. Ion channels embedded in the cell membrane allow specific ions to pass through, while ion pumps actively transport ions against their concentration gradients, using energy. Changes in ion permeability or flux can lead to alterations in the membrane potential, such as depolarization (becoming less negative) or hyperpolarization (becoming more negative). These changes are fundamental to cellular signaling.