has part has part has_part keratinocyte hair root sheath hair inner root sheath A multilayered tube composed of terminally differentiated hair follicle keratinocytes that is surrounded by the outer root sheath; the layers of the inner root sheath include the companion layer, Henle's layer, Huxley's layer and the inner root sheath cuticle[MP]. inner sheath of hair follicle UBERON:0005941 MA:0000779 hair follicle inner root sheath internal root sheath of hair follicle FMA:70935 BTO:0003971 inner root sheath inner root sheath of hair follicle EMAPA:32792