Myelin incisure

Myelin incisure

Diagram of longitudinal sections of medullated nerve fibers. (Incisure labeled at upper left.)
Identifiers
Code TH H2.00.06.2.03015
Dorlands
/Elsevier
12447772

Anatomical terminology

Myelin incisures (a.k.a. Schmidt-Lanterman clefts, Schmidt-Lanterman incisures, clefts of Schmidt-Lanterman, segments of Lanterman, medullary segments), are small pockets of cytoplasm left behind during the Schwann cell mylenation process. They are histological evidence of the small amount of cytoplasm that remains in the inner layer of the myelin sheath created by Schwann cells wrapping tightly around a nerve.

In the peripheral nervous system (PNS) axons can be either myelinated or unmyelinated. Myelination refers to the insulation of an axon with concentric surrounding layers of lipid membrane (myelin) produced by Schwann cells. These layers are generally uniform and continuous (similar in structure to a fruit roll up), but due to imperfect nature of the process by which Schwann cells wrap the nerve axon, this wrapping process can sometimes leave behind small pockets of residual cytoplasm displaced to the periphery during the formation of the myelin sheath. These pockets, or "incisures", can subdivide the myelinated axon into irregular portions. These staggered clefts also provide communication channels between layers by connecting the outer collar of cytoplasm of the Schwann cell to the deepest layer of myelin sheath.

References

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)

External links


This article is issued from Wikipedia - version of the Tuesday, June 09, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.