Here are the essential concepts you must grasp in order to answer the question correctly.
Saltatory Conduction
Saltatory conduction is a process by which action potentials jump from one node of Ranvier to another along myelinated axons. This mechanism allows for faster transmission of electrical signals in neurons compared to continuous conduction, where action potentials must propagate along the entire length of the axon. The myelin sheath insulates the axon, preventing ion leakage and facilitating rapid signal propagation.
Recommended video:
Types of Propagation: Saltatory Conduction
Nodes of Ranvier
Nodes of Ranvier are small gaps in the myelin sheath of axons where the axolemma is exposed. These nodes are crucial for saltatory conduction, as they contain a high density of voltage-gated sodium channels that allow for the rapid depolarization necessary to generate action potentials. The presence of these nodes enables the action potential to 'leap' from one node to the next, significantly increasing the speed of neural transmission.
Recommended video:
Introduction to Lymph Nodes
Action Potential Generation
An action potential is a rapid, temporary change in the electrical membrane potential of a neuron, triggered when the membrane depolarizes to a certain threshold. In the context of saltatory conduction, action potentials are generated only at the nodes of Ranvier, rather than along the entire axon. This selective generation of action potentials at the nodes is what allows for the efficient and rapid transmission of signals in myelinated neurons.
Recommended video: