Assertion (A) : Impulses are faster in myelinated nerves than unmyelinated ones.
Reason (R) : The impulse must travel the length of the myelinated neuron.
Both A and R are true and R is the correct explanation of A.
Both A and R are true but R is NOT the correct explanation of A.
A is true but R is false.
A is false but R is true.
Myelin accelerates action potential conduction by functioning as an electrical insulator. Unmyelinated axon conduction velocities, for example, range from around 0.5 to 10 m/s, but myelinated axons can conduct at speeds of up to 150 m/s. Hence assertion is true.
The nerve impulse jumps from one Ranvier node to the next in myelinated fibres. As a result, it is speedier. However, the impulse must travel the entire length of the non-myelinated fibre. As a result, it moves slowly. Hence reason is false. Therefore option C is correct.
As reason is false, option A and B are incorrect.
As assertion is true, option D is incorrect.
Hence, Option c is the correct answer.