NEET PG DENTAL EXAM

EMBRYOLOGY

NERVOUS SYSTEM

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
What is the purpose of the myelin sheath on the axon?
A
To maintain temperature
B
To improve conductivity
C
To protect the axon
D
To release neurotransmitters
Explanation: 

Detailed explanation-1: -By acting as an electrical insulator, myelin greatly speeds up action potential conduction (Figure 3.14). For example, whereas unmyelinated axon conduction velocities range from about 0.5 to 10 m/s, myelinated axons can conduct at velocities up to 150 m/s.

Detailed explanation-2: -Summary. Myelin can greatly increase the speed of electrical impulses in neurons because it insulates the axon and assembles voltage-gated sodium channel clusters at discrete nodes along its length.

Detailed explanation-3: -The myelin surrounding the neurons protects the axon and aids in the speed of transmission. The myelin sheath is broken up by points known as the nodes of Ranvier or myelin sheath gaps. Electrical impulses are able to jump from one node to the next, which plays a role in speeding up the transmission of the signal.

Detailed explanation-4: -Myelin has properties of low capacitance and high electrical resistance which means it can act as an insulator. Therefore, myelin sheaths insulate axons to increase the speed of electrical signal conduction. This allows myelinated axons to conduct electrical signals at high speeds.

There is 1 question to complete.