What is known about the myelin sheath?
Answers
Each myelin sheath is formed by the concentric wrapping of an oligodendrocyte or Schwann cell process around the axon. ... Due to its high prevalence, multiple sclerosis, which specifically affects the central nervous system (brain, spinal cord and optic nerve), is the best known disorder of myelin.
The myelin sheath is a protective covering that surrounds fibres called axons, the long thin projections that extend from the main body of a nerve cell or neuron. This sheath is composed of protein and lipids.
Most nerve fibres are surrounded by an insulating, fatty sheath called myelin, which acts to speed up impulses. The myelin sheath contains periodic breaks called nodes of Ranvier. By jumping from node to node, the impulse can travel much more quickly than if it had to travel along the entire length of the nerve fibre.
Although it is well-known that myelin can be repaired by oligodendrocytes if it is damaged, scientists do not understand the exact repair mechanisms used by these cells.
A recent study in mice demonstrated the potential in remyelination, which is the growth of lost myelin. The ability to regrow myelin could reverse the damages caused by multiple sclerosis (MS). Nerves are protected by a fatty myelin sheath.