Question

Explain the importance of the nodes of Ranvier and conduction in myelinated fibers as opposed to conduction in unmyelinated fibers (p. 378).

A) Nodes of Ranvier are irrelevant in myelinated fibers, and conduction is slower in myelinated fibers compared to unmyelinated fibers.
B) Nodes of Ranvier in myelinated fibers allow for the rapid, saltatory conduction of nerve impulses, which is more efficient than continuous conduction in unmyelinated fibers.
C) The nodes of Ranvier play a crucial role in unmyelinated fibers, while myelinated fibers have no nodes, resulting in faster conduction in unmyelinated fibers.
D) Conduction in myelinated fibers is impeded by the presence of nodes of Ranvier, whereas unmyelinated fibers allow for smooth and continuous conduction.

Answer 1

The nodes of Ranvier allow for rapid and efficient saltatory conduction in myelinated fibers, enabling faster signal transmission compared to the continuous conduction of unmyelinated fibers.

Step-by-step explanation:

The nodes of Ranvier are critical in the rapid signal transmission of myelinated fibers through saltatory conduction, which is more efficient than continuous conduction in unmyelinated fibers. Myelin acts as an insulator, speeding up the conduction by preventing current loss, while the nodes of Ranvier are gaps in the myelin sheath where action potentials are regenerated.

This saltatory conduction allows the action potential to 'jump' from node to node, increasing transmission speed without the need for continuous depolarization along the entire axon.