Question

Explain the properties of myelinated nerves in terms of the insulating properties of myelin.

a) Myelin increases nerve conduction speed by promoting depolarization.

b) Myelin decreases nerve conduction speed by inhibiting repolarization.

c) Myelin insulates nerve fibers, preventing the loss of electrical signals and promoting faster nerve conduction.

d) Myelin has no effect on nerve conduction.

Answer 1

Myelin enhances the speed of electrical signals in nerves by insulating axons and allowing action potentials to jump between nodes of Ranvier, through a process known as saltatory conduction.

Step-by-step explanation:

Myelinated nerves are characterized by the presence of myelin, a fatty substance that insulates axons and enhances the speed of electrical signal transmission. Myelination prevents the signal from losing voltage or 'leaking' and allows impulses to jump from node to node (saltatory conduction) rather than moving slowly along the entire length of the axon. This efficient propagation of the action potential occurs due to the insulating properties of myelin, which prevent the need for continual depolarization and repolarization along the myelinated stretches of the axons. Defects in myelination, such as those found in diseases like multiple sclerosis, lead to slowed nerve conduction and various neurological deficits.