A: Presence of myelin sheath increases the ra | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) The myelin sheath acts as an electrical insulator around the axon.Because of this insulation,ionic channels (voltage-gated $Na^+$ channels) are la

Vedclass · Accepted Answer

Assertion and Reason both are correct and Reason is the correct explanation of Assertion.

Vedclass · Answer

(A) The myelin sheath acts as an electrical insulator around the axon.Because of this insulation,ionic channels (voltage-gated $Na^+$ channels) are largely absent in the internodal regions covered by the myelin sheath.Consequently,depolarization can only occur at the nodes of Ranvier,where these channels are highly concentrated.This forces the action potential to 'jump' from one node to the next,a process known as saltatory conduction,which significantly increases the speed of nerve impulse transmission.

$A$: Presence of myelin sheath increases the rate of conduction of nerve impulse.
$R$: Ionic channels are absent in the area covered by myelin sheath; therefore,depolarization occurs only at the nodes of Ranvier,resulting in saltatory or jumping conduction.

Similar Questions

During the transmission of a nerve impulse,the potential inside the membrane undergoes which of the following changes in charge?

Chronaxie is defined as:

Assertion: The imbalance in concentration of $Na^+$,$K^+$ and proteins generates resting potential.
Reason: To maintain the unequal distribution of $Na^+$ and $K^+$,the neurons use electrical energy.

What happens during depolarization of the nerve membrane?

Vedclass Test Series

Exam Paper Generator

Online Exam Module

$A$: Presence of myelin sheath increases the rate of conduction of nerve impulse.$R$: Ionic channels are absent in the area covered by myelin sheath; therefore,depolarization occurs only at the nodes of Ranvier,resulting in saltatory or jumping conduction.