Propagation of Action Potential

What is Continuous Conduction?

Step-by-step depolarization and repolarization that occurs in unmyelinated axons and muscle fibers. It moves slower because it depolarizes each segment of the axon.

What is Saltatory Conduction?

Action potentials "jump" from one node of Ranvier to the next in myelinated axons, making it faster and more efficient than continuous conduction.

What happens under the Myelin Sheath during Saltatory Conduction?

lons cannot move under the myelin. The electrical current generated by sodium depolarizing the cell moves through the cytoplasm and extracellular fluid, stimulating a new action potential at the next node.

Why is the Myelin Sheath segmented?

The myelin sheath is segmented to ensure the electrical signal remains strong enough to reach the end of the axon by jumping from node to node.

How does Axon Diameter affect Conduction Speed?

Larger diameter axons conduct action potentials faster, while smaller diameter axons have slower conduction speeds.

How does Temperature affect Conduction Speed?

Conduction speed decreases when neurons are cooled.

What are the Nerve Fiber Types and their characteristics?

• A fibers: Largest diameter, myelinated, fastest conduction.

• B fibers: Intermediate diameter, myelinated, moderate conduction.

• C fibers: Smallest diameter, unmyelinated, slowest conduction.