Saltatory conduction is a type of nerve impulse conduction that allows action potentials to propagate faster and more efficiently. This type of conduction occurs in myelinated nerve fibers in the human body. When an action potential travels via saltatory conduction, the electrical signal jumps from one bare segment of fiber to the next, as opposed to traversing the entire length of the nerve's axon. Saltatory conduction gets its name from the French word saltare, which means "to leap." Saltation saves time and improves energy efficiency in the nervous system.

Action potentials are electrical impulses that act as signals to and from neurons and muscle cells. These nerve impulses are typically generated only in the axon of the nerve. The axon then conducts the electrical current to its final destination, which typically is a synapse. Voltage-gated ion channels along the length of the axon sustain the electrical current and keep it propagating.

In unmyelinated axons, these channels are directly adjacent to one another. Conduction is relatively slow in unmyelinated axons, because voltage-gated Na+ and K+ channels have to repeatedly regenerate the action potential at various points along the axon in order to keep the electrical current from decaying. In internal organs, such as the digestive system, blood vessels, or glands, these slower responses generally are not a problem. Bodily systems that typically need to react quickly — such as the central nervous system — rely more heavily on myelinated axons.

Myelin — a whitish, electrically insulating material composed of lipids and proteins — sheathes the length of myelinated axons. Segments of unmyelinated axon, called nodes of Ranvier, interrupt the myelin sheath at intervals. In the central nervous system, cells called oligodendrocytes produce myelin. They then wrap themselves around axons and squeeze their myelin contents out to envelope the axon. Schwann cells serve the same function in the peripheral nervous system.

The Myelin sheath acts an insulator and prevents electrical charges from leaking through the axon membrane. Virtually all the voltage-gated channels in a myelinated axon concentrate at the nodes of Ranvier. These nodes are spaced approximately .04 inches (about 1 mm) apart.

Action potentials propagate through myelinated nerve fibers via saltatory conduction. An electrical impulse cannot pass through the sheathed portions of the axon. Instead, the current jumps rapidly from one node to the next, where it triggers another action potential. This current leaps to the next neighboring node of Ranvier. The process continues as the electrical signal jumps from node to node along the length of the axon.

There are two main advantages to saltatory conduction: increased conduction velocity and improved energy efficiency. Saltatory conduction is about 30-times faster than continuous conduction. By limiting electrical currents to the nodes of Ranvier, saltatory conduction allows fewer ions to leak through the membrane. This ultimately saves metabolic energy — a significant advantage since the human nervous system typically uses about 20 percent of the body’s metabolic energy.