The nail matrix is the formative layer of cells at the base of the fingernail or toenail. This tissue consists of rapidly dividing skin cells that soon fill with the protein keratin. The matrix of finger nails consists of the most rapidly dividing skin cells in the body, which grow four times faster than toenails at a rate of about 3 mm a month.
A. Nail plate; B. lunula; C. root; D. sinus; E. matrix; F. nail bed; G. hyponychium; H. free margin.