CBSE Class 11-science Answered

Myelinated neurons have a membranous, lipid sheath called myelin. Myelin is a highly organized multilamellar structure formed by the plasma membrane of oligodendrocytes in the CNS and Schwann cells in the PNS. Myelin is an electrical insulator which allows increased speed of conduction along an axon.

Neurons which pass information about temperature change and prolonged ache need not conduct impulses very fast and thus can easily work at speeds of 0.5 meters/second. Hence, they lack myelin sheath and are non-myelinated. However, neurons which have to pass information about sudden pain, such as touching a burning hot pan, need to myelinated to protect the body against these kinds of dangers.