Formation of Wool

Surrounded by the inner root sheath, the fiber cells multiply and the constant stream of cell production pushes the fiber cells upward toward the skin surface. As the fiber cells move up the hair folhcle, they begin to differentiate into particular cell types cuticle and cortex. In addition to cuticle and cortex cells, the folhcle also produces a central strand of cells that are loosely organized, forming the medulla in the center of the hair fiber. Eventually, the tip of the fiber penetrates the superficial layers of the epidermis and the mature fiber emerges from the skin surface. In the mature fiber, cells are keratinized and hardened. 

Although the keratinized cells in a mature fiber already are dead, the fiber length continues to increase due to the formation of new fiber cells in the follicle. Mature fibers can be sheared after reaching certain length In most parts of the world, matrue fibers can be sheared once a year, in spring or sununer. Sheared fibers then can be sorted and graded for use. 

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