myeliinipunoksia

Myeliinipunoksia, often translated as myelin sheaths or myelin wrappings, refers to the fatty, insulating layer that surrounds nerve fibers, called axons, in the nervous system. This crucial structure is formed by specialized glial cells: oligodendrocytes in the central nervous system (brain and spinal cord) and Schwann cells in the peripheral nervous system (nerves outside the brain and spinal cord). These cells wrap their membranes around the axon multiple times, creating a segmented structure.

The primary function of myeliinipunoksia is to increase the speed at which nerve impulses, or action potentials, travel along the axon. This insulation prevents the leakage of electrical current and forces the impulse to jump between gaps in the myelin sheath, known as the nodes of Ranvier. This process, called saltatory conduction, is significantly faster than conduction along unmyelinated axons. Myelin also plays a role in protecting and supporting the axons.

Damage to the myeliinipunoksia, a process called demyelination, can severely impair nerve function. Conditions like multiple sclerosis (MS) and Guillain-Barré syndrome are characterized by the immune system attacking and destroying myelin, leading to a wide range of neurological symptoms such as muscle weakness, sensory disturbances, and coordination problems. The repair or regeneration of myelin, known as remyelination, is possible to some extent, but its efficiency varies depending on the cause and extent of the damage.