Root sheath
Encyclopedia
The inner or epidermic coat of the hair follicle
Hair follicle
A hair follicle is a skin organ that produces hair. Hair production occurs in phases, including a growth phase , and cessation phase , and a rest phase . Stem cells are principally responsible for the production of hair....

 is closely adherent to the root of the hair, and consists of two strata named respectively the outer and inner root sheaths;

Outer Root Sheath

The outer root sheath corresponds with the stratum mucosum (Stratum germinativum
Stratum germinativum
The stratum basale is the deepest layer of the five layers of the epidermis, which is the outer covering of skin in mammals. The stratum basale is a continuous layer of cells...

 and Stratum Spinosum
Stratum spinosum
The stratum spinosum is a layer of the epidermis found between the stratum granulosum and stratum basale. This layer is also referred to as the "spinous" or "prickle-cell" layer. This appearance is due to desmosomal connections of adjacent cells. Keratinization begins in the stratum spinosum....

) of the epidermis, and resembles it in the rounded form and soft character of its cells; at the bottom of the hair follicle these cells become continuous with those of the root of the hair.

Inner Root Sheath

The inner root sheath consists of
  • (1) a delicate cuticle next the hair, composed of a single layer of imbricated scales with atrophied nuclei;
  • (2) Huxley's layer
    Huxley's layer
    The second layer of the inner root sheath of the hair consists of one or two layers of horny, flattened, nucleated cells, known as Huxley's layer....

  • (3) Henle's layer
    Henle's layer
    Henle's layer is the third layer of the inner root sheath of the hair, consisting of a single layer of cubical cells with clear flattened nuclei....



The term "trichilemmal" refers to the outer root sheath.

External links

  • http://trc.ucdavis.edu/mjguinan/apc100/modules/Integument/hair/hair3/hair3.html
  • http://education.vetmed.vt.edu/Curriculum/VM8054/Labs/Lab15/Lab15.htm
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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