The inner root sheath or internal root sheath of the hair follicle is located between the

outer root sheath The outer root sheath or external root sheath of the hair follicle encloses the inner root sheath and hair shaft.James, William; Berger, Timothy; Elston, Dirk (2005) ''Andrews' Diseases of the Skin: Clinical Dermatology'' (10th ed.). Saunders. Pag ...

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 Henle's layer is the third and the outermost layer of the inner root sheath of the hair follicle, consisting of a single layer of cubical cells with clear flattened nuclei. It is named after German physician, pathologist and anatomist A ...

Huxley's layer Huxley's layer is the second layer of the inner root sheath of the hair and consists of one or two layers of horny, flattened, nucleated cells. It lies between Henle's layer and the cuticle. The layer is named after English biologist Thomas Henry ...

, 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 ...

. 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 Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, hor ...

. Huxley's layer is in the middle, made up of approximately two rows of flattened cells with granular

protoplasm Protoplasm (; ) is the living part of a cell that is surrounded by a plasma membrane. It is a mixture of small molecules such as ions, monosaccharides, amino acid, and macromolecules such as proteins, polysaccharides, lipids, etc. In some defini ...

. The cuticle of the root sheath is in the center, continuous with the outermost layer of the hair fiber.

References

Hair anatomy {{Dermatology-stub