inner root sheath
{{Short description|Region of hair follicle}}
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. {{ISBN|0-7216-2921-0}}. It is made of three layers: Henle's layer, Huxley's layer, and the cuticle.{{citation |title=A text-book of histology
|url=https://books.google.com/books?id=lsEEAQAAIAAJ&pg=PA359 |pages=359–560 |first= Frederick Randolph |last=Bailey |publisher=W. Wood, University of California |year=1910 }} 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.{{cite journal|pmc=3129131|journal=Int J Trichology|date= 2011|volume=3|issue=1|pages=57–62|doi= 10.4103/0974-7753.82119|pmid= 21769243|title=The Inner Root Sheath and the Men Associated with it Eponymically |author=Rajiv S Joshi |doi-access=free }} Huxley's layer is in the middle, made up of approximately two rows of flattened cells with granular protoplasm. The cuticle of the root sheath is in the center, continuous with the outermost layer of the hair fiber.