Full Text

Anatomy and biology of the nail unit


[1–5] The component parts of the nail apparatus are shown diagrammatically in Fig. 65.1 . The rectangular nail is firmly attached to the nail bed; it is less adherent proximally, apart from the posterolateral corners. Approximately one-quarter of the nail is covered by the proximal nail fold, and a narrow margin of the sides of the nail plate is often occluded by the lateral nail folds. Underlying the proximal part of the nail is the white lunula (half-moon, lunule); this area represents the most distal region of the matrix [6] . It is most prominent on the thumb and great toe and may be partly or completely concealed by the proximal nail fold in other digits. The reason for the white colour is not known [7–9] . The natural shape of the free margin of the nail is the same as the contour of the distal border of the lunula. The nail plate distal to the lunula usually appears pink, due to its translucency, which allows the redness of the vascular nail bed to be seen through it. The proximal nail fold has two epithelial surfaces, dorsal and ventral; at the junction of the two, the cuticle projects distally onto the nail surface. The lateral nail folds are in continuity with the skin on the sides of the digit laterally, and medially they are joined by the nail bed. Some authorities term the lateral nail fold and adjacent tissue lateral to the nail fold the ‘nail wall’. Fig. 65.1 ... log in or subscribe to read full text

Log In

You are not currently logged-in to Blackwell Reference Online

If your institution has a subscription, you can log in here:


     Forgotten your password?

Find out how to subscribe.

Your library does not have access to this title. Please contact your librarian to arrange access.

[ access key 0 : accessibility information including access key list ] [ access key 1 : home page ] [ access key 2 : skip navigation ] [ access key 6 : help ] [ access key 9 : contact us ] [ access key 0 : accessibility statement ]

Blackwell Publishing Home Page

Blackwell Reference Online ® is a Blackwell Publishing Inc. registered trademark
Technology partner: Semantico Ltd.

Blackwell Publishing and its licensors hold the copyright in all material held in Blackwell Reference Online. No material may be resold or published elsewhere without Blackwell Publishing's written consent, save as authorised by a licence with Blackwell Publishing or to the extent required by the applicable law.

Back to Top