What Is the Myelin Sheath?

Myelin sheath is a layer of membrane wrapped around the axons of nerve cells, that is, myelin sheath is composed of Schwann cells and myelin cell membranes. Its role is to prevent electrical impulses from being transmitted from a neuron axon to another neuron axon.

Myelin sheath

Myelin sheath is wrapped in nerve cells

Myelin sheath

It is currently known that myelin has three functions:

The first is to support electrical insulation between axons and surrounding tissues, such as adjacent axons, to avoid interference;

The second is to speed up the transfer of action potentials through a mechanism called "jump conduction";

The third is to guide the regeneration of axons when some axons are damaged.

The antigenicity of MBP mainly depends on its primary structure. Experimental studies have shown that different kinds of experimental animals have different immune responses to different fragments in the amino acid sequence. Active immunization of experimental animals with bovine MBP can cause experimental allergic encephalomyelitis (EAE). Among them, amino acids 114 to 122 and amino acids 117 to 170 have strong antigenicity to guinea pigs and monkeys, respectively. It is more noticed that the myelin sheath and its supporting cells (oligodendrocytes, Schwann cells) are damaged by attack by different immune mechanisms, such as immunoglobulins, MOG antibodies, etc.

Langfie knot on the myelin sheath can make nerve impulse transfer.

Myelin sheath is a layer of adipose tissue, which is wrapped around the axons of certain neurons. It has an insulating effect and improves the conduction speed of nerve impulses. It also protects axons. The importance of myelin sheath is apparent in multiple sclerosis, which is a disease with degraded myelin function. Illness can slow the transmission of information to muscles and eventually lose control of the muscles.