Understanding Nail Structure
Nail Structure ~ The Nail Plate
The tough outer portion of the nail—the part you trim, file, polish, and buff—is called the nail plate. You might be surprised to learn that the nail plate is composed chiefly of keratin, the same structural protein found not only in hair but also in the epidermal layer of “regular” skin.
The keratin in your nails, however, contains more sulfur than the keratin in your hair and skin; and it is this high sulfur content that gives the nails their hardness. Now, keratin—whether of the hard variety found in your nails or the soft variety found in your skin’s epidermis—is a protein that likes to layer.
Consequently, the nail plate, like the epidermis, is a layered affair, a fact you can observe for yourself if you look very closely at the cut portion of a clipped toenail. Fatty acids called phospholipids in the upper and lower layers of the nail plate provide the resilience and flexibility that enable the nail to bend some without breaking.
The nail plate itself, by the way, is not alive, and thus cannot be “fed,”“nourished,” or “replenished” with anything you’ll encounter on a drugstore or supermarket shelf. Like the hair shaft, it is an inorganic (or non-living) outgrowth produced by a nucleus of living, reproductive cells at its base.
Nail Structure ~ The Nail Matrix
This collection of live cells is known as the nail matrix. Most of the nail matrix lies hidden from view beneath the posterior nail fold at the back of each nail. But a small, white, crescent-shaped segment of it called the lunula can be seen near the nail base.
Two other important parts of the nail are the cuticle and the nail bed. The cuticle, as you probably know, is an opaque (or semitransparent) skin fold at the base of the nail plate. This tender, delicate, slightly scrunched lip of dead skin per- forms a pair of vital functions: First, it connects and secures the nail plate to the skin of the finger or toe to which it belongs; and second, it shields the vulnerable nail base from foreign objects and infection.
If you’re one of those women who find cuticles unattractive, you’ll want to exercise real care and caution when you try to push them out of sight. Your nails need the protection offered by the cuticles, and they are easily damaged by trimming (a definite don’t) and overly aggressive pushing and prodding (which, if it must be done at all, should be done gently, as we’ll demonstrate shortly).
Nail Structure ~ The Nail Bed
The nail bed, for its part of the nail structure, is a soft, thick layer of grooved tissue that lies beneath the nail plate and acts as a sort of “shock absorber” for the nail above. When someone, say, steps on your big toe at a dance or accidentally closes a door on the tips of your fingers, the resulting damage to the nail is minimized—though by no means eliminated—by the cushioning effect of the bed.
In addition, the nail bed shelters the extensive network of tiny blood vessels that carry necessary nutrients and oxygen to the nail matrix, as well as the sensitive nerve endings that let your brain know what’s new and exciting at the outermost extremities of the body.
Facts About Nail Growth
Your fingernails are constantly growing, your health and diet can effect just how fast your nails grow.