MadSci Network: Anatomy

Re: Meaning of Fingernail Moons

Date: Thu Jun 1 17:05:19 2000
Posted By: June M. Wingert , RM(NRM),Research Associate
Area of science: Anatomy
ID: 959277169.An

Below you will find everything you need to know about the Lunula.
m http://www.nh.u

Matrix.  The matrix is a highly specialized epithelial
structure that manufactures the bulk of the nail plate. It
grows and matures like other epithelial structures and
produces a highly dense and compacted stratum corneum
called the nail plate. The flat, oval shaped, matrix extends
from under the proximal nail fold to just beyond the
proximal portion of the visible part of the nail plate. A
little more than one-third of the matrix is seen through the
nail plate as the white half-moon shaped lunula. The
epithelium of the proximal nail fold and the proximal
portion of the matrix under the nail fold makes the top
portion of the nail plate. The distal matrix (lunula) makes
the bottom of the nail plate that is bonded to the nail bed,
it is a lighter color as it mixes with the matrix cells.

The lunula. 

                       Cohen PR 
Department of Dermatology, University of 
Texas-Houston Medical School 77030, USA.
The lunula is the visible portion of the distal nail matrix that extends 
beyond the proximal nailfold.
It is white, half-moon-shaped, appears by week 14 of gestation, has unique 
histologic features.
The lunula has a primary structural role in defining the free edge of the 
distal nail plate. Lunular anomalies include changes in form and structure 
and in color. Lunular dysmorphologic features can be characterized by 
macrolunula, microlunula or anolunula, and nonconvex lunula. Lunular
dyschromias can be confluent or spotted or can be characterized by 
longitudinal colored bands that traverse the lunula. Alterations in the 
morphologic features or color (or both) of the lunula can be an indication 
of either a cutaneous or a systemic disorder.


     - nail plate:
          - comprised of concentrated, adherent interdigitating cells which
                have no nuclei or organelles;
     - germinal matrix:
          - comprised of cells which contribute to 90% growth of the new 
          - distal edge of the germinal matrix is demarcated by the edge of 
          - there is minimal adherence of germinal matrix to the nail;
     - sterile matrix:
          - extends distal to the lunula;
          - responsible for adherence of nail to nail bed;
m http://www.nh.u
m http://www.nh.u

Hope this helps .

June Wingert
Research Associate
Lexicon Genetics
The Woodlands Texas

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