The myelin it is situated in the nervous system, forming pods They are responsible for surrounding the axons of neurons. It is a phospholipid bilayer system consisting of sphingolipid , which enables the transmission of nerve impulses to the various body regions through an insulating effect.
Myelin is a sphingophospholipid that is formed by sphingol , an alcohol composed of a chain of choline, phosphate and fatty acid. In the spinal and cranial nerves, as well as in the peripheral nervous system (SNP), myelin sheaths are formed thanks to the schwann cells that produce layers of proteins and lipids.
It is in the membrane of this small cell class where myelin is found: since the schwann cells they are successively rolled in the axons, give rise to the pods.
The myelin sheath is responsible for wrapping the axon with the exception of Ranvier nodules (which are those places located between the myelin sheaths). Myelin functions as an electrochemical insulator that allows the nerve impulse to be transmitted to jumps from node to node.
The situation within the central nervous system (SNC ) is different since, in this case, myelin is made up of oligodendrocytes (another class of cells that have numerous dendrites).
It is common to talk about "white matter" and "Gray matter" in the brain. Myelin is responsible for the color of white matter, while those non-myelinated axons make up gray matter.
If a person, due to a disorder, loses myelin, he will suffer from major problems in his nervous system. The electrical impulses, in the absence of this substance, will not complete its path or circulate very slowly, as is the case diseases as the multiple sclerosis .
However, it should also be stressed that in addition to this disease, others may occur in the patient, such as amyotrophic lateral sclerosis, also called Charcot disease, which is characterized by degenerative type and results in a progressive muscular paralysis that ends in death.
Similarly, other diseases caused by myelin are Baló's concentric sclerosis, which is neurological and occurs as a result of the rapid loss of the envelope that covers the said myelin, or leukodystrophies. The latter in particular also occur as a result of the degeneration of the fat of the latter and among its most frequent symptoms are visual or motor class alterations.
And all this, without forgetting that there are other pathologies that are also directly related to myelin. This would be the case of the central pontine myelinolysis, Devic syndrome or Marchiafava-Bignami disease. Atrophy of the corpus callosum is also known as the latter pathology, which is a very rare encephalopathy.
People with chronic alcoholism are the ones who can be most affected by this disease that results in a series of symptoms such as personality changes, seizures, hallucinations, voice changes, or notable lack of intelligence. However, we can establish that there are two clearly differentiated types: the one in which the damage is slight and the one in which the patient will reach the coma or even suffer a stupor.