What is the name of the electrical impulse that leads to the excitation of muscle fibers?

The term that describes the electrical impulse leading to the excitation of muscle fibers is related to the concept of "twitch." A twitch represents the response of a muscle fiber to a single electrical impulse. When a muscle fiber is stimulated by an electrical impulse from a motor neuron, it depolarizes, leading to a brief contraction known as a twitch. This twitch is critical in understanding how muscle fibers respond to stimulus, as it reflects the muscle’s ability to react to signals effectively.

The other terms provided are not specific to the electrical impulse. While "impulse" may describe a general electrical signal, it doesn’t specifically relate to the physiological response in muscles. "Summation" refers to the process where multiple stimuli lead to greater muscle contraction, and "contraction" itself describes the shortening of the muscle fibers resulting from excitation but does not reference the initial electrical impulse. Understanding these distinctions is crucial for grasping how muscles function in response to electrical signals.