What is saltatory conduction?

Saltatory conduction is a process that occurs in myelinated axons, where the electrical impulse "jumps" from one node of Ranvier to another. These nodes are gaps in the myelin sheath that insulates the axon. Myelin, which is made up of fatty tissue, acts as an insulator and allows the action potential to travel much faster than it would along unmyelinated fibers.

During saltatory conduction, when an action potential is generated at one node, it depolarizes the membrane at that site, which leads to a rapid spread of the electrical signal along the axon. The myelination reduces capacitance and increases membrane resistance, enabling the impulse to propagate swiftly via these jumps, rather than continuously along the entire length of the axon. This mechanism is energy-efficient and significantly speeds up the conduction velocity of nerve impulses, making it a critical feature of neuronal communication in the nervous system.

The other options address related concepts but do not define saltatory conduction correctly. An electrical chain reaction between cells describes synaptic transmission rather than conduction along an axon. The fatty tissue surrounding nerves refers to myelin but does not capture the active conduction process. The abrupt change of polarity reflects the action potential mechanism but