Schmidt-Lanterman incisures

Schmidt-Lanterman incisures
Diagram of longitudinal sections of medullated nerve fibers. (Incisure labeled at upper left.)
Gray's	subject #183 727
Dorlands/Elsevier	i_05/12447772

Overview

In the peripheral nervous system (PNS) axons can be either myelinated or unmyelinated. Myelination means that the axon is insulated by surrounding it with layers of fatty membrane (myelin). These layers are continuous (like rolling up rope), but due to the way they are formed they often include small amounts of cytoplasm. These are the so called Schmidt-Lanterman cleft (a.k.a. Schmidt-Lanterman incisures,clefts of Schmidt-Lanterman, segments of Lanterman, medullary segments), which subdivide the myelinated axon into irregular portions. 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.

External links

• Schmidt-Lanterman+incisures at eMedicine Dictionary
• Histology at Boston University 22801loa
• Slide at umdnj.edu

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.