schwannów

Schwannów refers to the Schwann cells, glial cells of the peripheral nervous system named after Theodor Schwann. They envelop axons to form the myelin sheath, which increases the speed of electrical impulse conduction and supports axon survival. Schwann cells also play a key role in peripheral nerve regeneration after injury.

There are two main forms of Schwann cells: myelinating Schwann cells, which wrap around a single axon segment to form a multi-layered myelin sheath; and non-myelinating Schwann cells (Remak glia), which enclose several small-diameter axons within a common envelope without producing a compact myelin sheath. The myelin sheath consists of concentric layers of Schwann cell membranes; gaps between segments are the nodes of Ranvier, which facilitate saltatory conduction. In unmyelinated fibers, the Schwann cell membranes hug the axons but do not form thick myelin lamellae.

Developmentally, Schwann cells are derived from neural crest cells and mature under signals such as neuregulins. They express markers including S100 and p75NTR, and they produce myelin proteins such as myelin basic protein (MBP) and protein zero (P0/MPZ).

Injury and repair, Schwann cells dedifferentiate, proliferate, and form bands of Büngner that guide regrowing axons. They also clear myelin debris and secrete neurotrophic factors to support regeneration.

Clinical relevance includes mutations in Schwann cell myelin proteins (e.g., MPZ, PMP22) causing Charcot–Marie–Tooth disease, and Schwann cell dysfunction contributing to peripheral neuropathies and autoimmune conditions like Guillain–Barré syndrome. In Polish texts, these cells are commonly referred to as komórki Schwanna.