What is the sequence of events that occurs during the formation of an impulse?

The sequence of events during the formation of an impulse begins when a stimulus captures the neuron's attention, leading to depolarization. Upon receiving a sufficient stimulus, the neuron's membrane potential becomes less negative, which is known as depolarization. This occurs when sodium channels open, allowing sodium ions to flow into the neuron, causing the internal environment to become more positive relative to the outside.

As depolarization reaches a certain level, termed the threshold, it triggers the generation of an action potential, which is the actual impulse. The action potential propagates along the neuron's axon, allowing the signal to travel quickly. This entire process defines how signals are initiated and transmitted in the nervous system. Understanding this sequence highlights the fundamental mechanics of neuronal communication and how stimuli are transformed into electrical signals, which are crucial for various physiological responses and actions.