Every neuron definitely has a myelin coating. However, not all have an adequate amount of it. Myelin supports conduction of the cells. It is known as the white lipid protein that supports myelination of a certain ganglia.
Myelination, on the other hand, is a process in which the neurolemmocyte or oligodendrocyte surrounds a certain part of the axon or dendrite. It occurs both in the central nervous system and the peripheral nervous system.
Myelin creates the white matter that could be seen in the brain. It is also responsible for the whitish color of the nerves and the spinal cord. In the peripheral nervous system, myelination occurs during the growth of neurolemmocytes around the axon or dendrite. The outer myelin sheath is surrounded by another sheath, called as a glycoprotein neurolemmal sheath. It is then responsible for the myelin’s protection and regeneration by the time it will experience tearing or injury.
Each axon is partially enveloped in a myelin sheath, having gaps of about 1 millimeter between the adjacent lemmocytes. The gap or the gaps then is called as the neurofibril nodes. These are responsible for the neuron’s nerve impulse propulsion. Meanwhile, a neurolemmocyte forms one sheath at a time- its size is about one axon. On the other hand, oligodendrocyte forms multiple sheaths at once.