myeliinitupen

Myeliinituppi is the myelin sheath, a fatty insulating layer that surrounds nerve fibers in the nervous system. This sheath is not continuous but is interrupted at regular intervals by gaps called nodes of Ranvier. The myelin sheath is produced by specialized cells: Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. These cells wrap their cell membranes multiple times around the axon, creating the layered structure of myelin.

The primary function of the myelin sheath is to increase the speed of nerve impulse conduction. The myelin acts as an electrical insulator, preventing the leakage of ions across the axon membrane. This allows the electrical signal, or action potential, to jump from one node of Ranvier to the next in a process called saltatory conduction. This significantly speeds up transmission compared to unmyelinated axons. Myelin also provides support and protection to the axon. Damage to the myelin sheath, as occurs in diseases like multiple sclerosis, can severely impair nerve function, leading to a variety of neurological symptoms.