Tulane University defines an ore as a body of material from which one or more valuable substances can be extracted. For example, bauxite ore is mined and refined to extract aluminum.
root sheath the epidermic layer of a hair follicle. sheath of Schwann neurilemma. synovial sheath synovial membrane lining the cavity of a bone through which a tendon moves. tendon sheath a lubricated fibrous or synovial layer of tissue in which the tendon is housed and through which it moves.
Around the papilla is the hair matrix, a collection of epithelial cells often interspersed with the pigment-producing cells, melanocytes. Cell division in the hair matrix produces the cells that form the major structures of the hair fiber and the inner root sheath.