List of abbreviations
of micros-
specialist terms
explained in
English +

Every attempt was made to provide correct information and labelling, however any liability for eventual errors or incompleteness is rejected!

dieser Seite

Dr. med.
H. Jastrow

of use
Overview Schwann cells (Gliocyti peripherici):
Pages with explanations are linked to the text below the images if available! (Labelling is in German)
non-myelinated nerve
Schwann cell (rat)
non-myelinated nerve fibres in a
Schwann cell, colon (rat)
myelinated nerve fibre +
Schwann cell (monkey)
myelinated nerve fibre
+ Schwann cell 2 (rat)
myelinated nerve fibre
Schwann cell 1 (rat)
myelinsheath of a fibre in vestibulo-
cochlear nerve (guinea pig)
node of Ranvier in cross-
section (monkey)
node of Ranvier in longi-
tudinal section (monkey)
idem + Schmidt-Lanter-
man incisure (monkey)
node of Ranvier in longi-
tudinal detail (monkey)
Schmidt-Lanterman's incisure
in longitudinal section (monkey)
non-myelinated nerve of Tela
submucosa, stomach (rat)
myelinated and non-my-
elinated axons (monkey)
myelinated and non-myelinated nerve
fibres in the nervus vagus esophagus (rat)
detail thereof inner + outer mesaxon on
myelin sheath (monkey)
detail 1: inner mes-
axon (monkey)
detail 2: outer
mesaxon (monkey)

Schwann cells (Neurolemmocytes; Terminologia histologica: Schwannocyti; Neurolemmocyti) form the myelin sheaths (Terminologia histologica: Stratum myelini) in peripherical (= nerve tissue apart from CNS, i.e. apart from brain and spinal cord) myelinated nerves and wrap the non-myelinated nerve cell processes (axons or dendrites) with one layer of their cell membrane and cytoplasm. Schwann cells nutrify and insulate the axons (impulse conducting processes of nerve cells to other cells) as well as dendrites (impulse receiving processes of nerve cells) of nerves. They may have a length of over 100 µmThe myelin sheath (Terminologia histologica: Stratum myelini) is formed by multiple, often far over 20 layers of closely attached cell membrane of a Schwann cell. The outer mesaxon (Terminologia histologica: Mesaxon externum) is the connection of the outer cell membrane to the compact myelin sheath. The inner mesaxon (Terminologia histologica: Mesaxon internum) is the connection between the myelin sheath and the inner part of the cell membrane of the Schwann cell which is directly opposite the axolemma, i.e. the cell membrane of the nerve fibre ensheated by the Schwann cell.
The term terminal Schwann cells (terminal neurolemmocytes, terminal glial cells; Terminologia histologica: Schwannocyti terminales, Neurolemmocyti terminales, Cellulae telogliales) is used for the Schwann cells at the end of nerve cell processes e.g., in tactile corpuscules. where they often form plate like processes in between the dendritic terminalsTogether with the other Schwann cells and the satellite glia cells of ganglia they comprise the peripheral glial cells (Terminologia histologica: Gliocyti peripherici).
At the border between two neighbouring Schwann cells a myelin sheath gap called node of Ranvier (Terminologia histologica: Nodi interruptionis myelini) is formed along the related nerve fibre. The nodes of Ranvier are the morphological base for saltatory impulse transduction which is very fast.
Further, there are Schmidt-Lanterman incisures (Terminologia histologica: Incisura myelini; see this image), oblique interruptions of the myelin sheath, i.e. myelin clefts or incisures where some Schwann cell cytoplasm is present between the myelin layers and gap junctions are seen in the membrane layers for quick passage of small molecules.

--> classification of nerve fibres
--> nerve, nerve tissue, central nervous system
--> Electron microscopic atlas Overview
--> Homepage of the workshop

Ten images were kindly provided by Prof. H. Wartenberg; other images, page & copyright H. Jastrow.