Chapter 9 Nail structure and growth
hyponychium
slightly thickened layer of skin under the nail that lies between the fingertip and free edge of the natural nail plate.
sidewall
also known as lateral nail fold; the fold of skin overlapping the side of the nail.
natural nail
also known as onyx; the hard protective plate is composed mainly of keratin, the same fibrous protein found in skin and hair. The keratin in natural nails is harder than the keratin in the skin or hair.
matrix
area where the nail plate cells are formed; this area is composed of matrix cells that produce the nail plate.
nail unit
composed of several major parts of the fingernail including the nail plate, nail bed, matrix, cuticle, eponychium, hyponychium, specialized ligaments, and nail fold. Together, all of these parts form the nail unit.
cuticle
dead, colorless tissue attached to the natural nail plate.
nail folds
folds of normal skin that surround the natural nail plate
nail groove
furrow on each side of the nail.
nail plate
hardened keratin plate that sits on and covers the natural nail bed. It is the most visible and functional part of the natural nail unit.
eponychium
living skin at the base of the natural nail skate that covers the matrix.
free edge
part of the nail plate that extends over the tip of the finger or toe.
nail bed
portion of the living skin that supports the nail plate as it grows toward the free edge.
perionychium
the tissue bordering the root and sides of a fingernail or toenail.
bed epithelium
thin layer if tissue that attaches the nail plate and the nail bed.
ligament
tough band of fibrous tissue that connects bones or holds an organ in place.
lunula
visible part of the matrix that extends from underneath the living skin; it is the whitish, half moon shape at the base of the nail.
nail malformation
when the nail is abnormal in shape or form.