Ranvier refers to the small gaps in the myelin sheath that surrounds nerve fibers. These gaps, known as Nodes of Ranvier, play a crucial role in the conduction of electrical impulses along the axon. By allowing ions to flow in and out of the neuron, they facilitate a process called saltatory conduction, which speeds up signal transmission. The discovery of Ranvier is attributed to the French histologist Louis Antoine Ranvier, who studied nerve tissues in the late 19th century. His work helped to enhance the understanding of how nerve signals are propagated, contributing significantly to the field of neurobiology.