What is impulse in the nervous system?

Impulse in the nervous system refers to the propagation of electrical signals along neurons, which are the basic units of communication in the nervous system. These electrical signals are called action potentials and they transmit information from one neuron to another, allowing for rapid and coordinated communication within the nervous system.

When a neuron receives a signal from another neuron or from sensory receptors, it generates an action potential. This involves a change in the electrical potential across the neuron's membrane, causing a wave of depolarization to travel along the neuron's axon. The axon is a long, slender projection of the neuron that transmits the action potential away from the cell body.

During an action potential, the membrane of the neuron becomes more permeable to certain ions, such as sodium and potassium, which flow in and out of the cell, causing a reversal of the electrical potential. This change in potential propagates along the axon, creating an electrical impulse that travels toward the neuron's synaptic terminals, where it can transmit the signal to other neurons or target cells.

The propagation of impulses in the nervous system allows for rapid and long-distance communication between different parts of the body. It underlies various physiological processes, including sensory perception, motor control, cognitive functions, and coordination of bodily systems.