The external epithelial root sheath of a hair (or hair follicle) is one of the two layers of the dermal root sheath, which is sometimes called simply the "root sheath" of a hair. The dermal root sheath of a hair consists of two layers of epidermal surrounded by an outer sheath of connective tissue.
The two layers of the dermal root sheath are:
The external epithelial root sheath consists of several layers of cuboid epithelial cells visible when stained with H&E stain, a histology stain.
