The inner root sheath or internal root sheath of the hair follicle is located between the
outer root sheath and the hair shaft.
[James, William; Berger, Timothy; Elston, Dirk (2005) ''Andrews' Diseases of the Skin: Clinical Dermatology'' (10th ed.). Saunders. Page 8. .] It is made of three layers:
Henle's layer,
Huxley's layer, and the
cuticle
A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...
.
The inner root sheaf serves to protect growing hair.
Description
Henle's layer is the outermost layer of the inner root sheath, consisting of a single row of
cubical cells. During his original examination, Henle believed the layer lacked
nuclei because he viewed it at a level where it had already
cornified.
Huxley's layer is in the middle, made up of approximately two rows of flattened cells with granular
protoplasm
Protoplasm (; ) is the part of a cell that is surrounded by a plasma membrane. It is a mixture of small molecules such as ions, monosaccharides, amino acids, and macromolecules such as proteins, polysaccharides, lipids, etc.
In some definitions ...
. The cuticle of the root sheath is in the center, continuous with the outermost layer of the hair fiber.
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References
Hair anatomy
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