Myeliinivä

Myeliinivä, derived from the Finnish word for myelin, refers to the fatty, insulating sheath that surrounds nerve fibers in the central and peripheral nervous systems. This protective layer, composed primarily of lipids and proteins, plays a crucial role in the efficient transmission of electrical signals along neurons. Myeliinivä allows nerve impulses to travel much faster than they would in unmyelinated axons through a process called saltatory conduction, where the impulse "jumps" between gaps in the myelin sheath known as nodes of Ranvier.

The formation of myeliinivä is carried out by specialized glial cells. In the central nervous system, oligodendrocytes are responsible for myelinating multiple axons simultaneously. In the peripheral nervous system, Schwann cells perform this function, with each Schwann cell myelinating a single segment of an axon. The integrity of myeliinivä is vital for proper neurological function.

Damage to myeliinivä, known as demyelination, can significantly impair nerve signal transmission, leading to a range of neurological disorders. Conditions such as multiple sclerosis, Guillain-Barré syndrome, and certain leukodystrophies are characterized by the progressive loss or damage of myeliinivä. Research into understanding and potentially repairing myeliinivä is a significant area of focus in neuroscience and neurology.