Närviimpulssidena

Närviimpulssidena, known in English as nerve impulses or action potentials, are the fundamental units of communication within the nervous system. These are electrochemical signals that travel along nerve cells, or neurons, allowing them to transmit information rapidly throughout the body. A nerve impulse is generated when a neuron is stimulated, causing a rapid change in the electrical charge across its cell membrane. This change involves the movement of ions, primarily sodium (Na+) and potassium (K+), in and out of the neuron.

The process begins with a stimulus that causes depolarization, where the inside of the neuron becomes more positive. If this depolarization reaches a certain threshold, an action potential is triggered. This action potential then propagates down the axon, the long projection of the neuron, like a wave. At the end of the axon, the impulse triggers the release of neurotransmitters, chemical messengers that can excite or inhibit other neurons, muscles, or glands, thus continuing the communication chain. This intricate signaling system is crucial for everything from sensing the environment to controlling voluntary movements and regulating bodily functions.