Taugaboðspennunnar

Taugaboðspennunnar, often translated as "nerve impulse voltage" or "action potential," refers to the rapid, transient change in electrical potential across the membrane of a neuron or muscle cell. This electrical signal is fundamental to cellular communication and function in excitable tissues. The resting state of a neuron's membrane is characterized by a negative electrical potential, maintained by ion gradients and membrane proteins. When a stimulus of sufficient magnitude is applied, it triggers the opening of voltage-gated sodium channels, leading to a rapid influx of sodium ions. This influx causes a reversal of the membrane potential, making the inside of the cell positive relative to the outside – this is the depolarization phase. Immediately following depolarization, voltage-gated potassium channels open, allowing potassium ions to flow out of the cell. This outward movement of positive charge repolarizes the membrane, restoring it towards its negative resting potential. A brief period of hyperpolarization, where the membrane potential becomes even more negative than the resting potential, often occurs before returning to the stable resting state. This entire sequence constitutes the action potential, which propagates along the length of the axon, enabling the transmission of information between neurons and to effector cells. The precise characteristics of the action potential, including its amplitude and duration, are crucial for encoding the strength and timing of neural signals.