cortices. 1  1a (1) : the outer or superficial part of an organ or bodily structure (such as the kidney, adrenal gland, or cerebellum or a bone); especially : cerebral cortex (2) : the proteinaceous usually pigmented layer of a hair below the cuticleb : the outer part of some organisms (such as paramecia)
If a toenail has completely fallen off, it can take up to 18 months for it to grow back. A toenail can take longer to grow back if the nail bed has permanent damage. In some cases, old nails do not completely fall off, and they act as a protective...
If you lose a fingernail, it will take four to six months to regrow completely. Toenails take a year to a year and a half to grow from cuticle to tip [source: Robb-Nicholson]. If you notice a change in your nails or their growth rate, see your doctor. For more information on nails and how they grow, see the links on the following page. 1.