Nails are attached to the nail bed (also known as the sterile matrix) by direct adhesion and interlocking of the nail plate with the structures of the nail bed itself.
The nail bed, located underneath the nail plate and attached to the distal phalanx (the bone in the fingertip or toe), is a specialized structure that facilitates nail growth and adherence. Here's a breakdown of how the nail plate is attached:
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Direct Adhesion: The underside of the nail plate and the surface of the nail bed are in close contact. This close proximity allows for some degree of direct adhesion.
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Interlocking Structures: The nail bed surface isn't perfectly smooth. It features longitudinal grooves and ridges that interlock with corresponding structures on the underside of the nail plate. This interlocking provides mechanical stability and contributes to the nail's attachment.
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Continuous Growth from the Nail Matrix: The nail matrix, located beneath the proximal nail fold, is the source of new nail cells. As these cells divide and keratinize (harden), they push older cells forward, forming the nail plate. This continuous growth process effectively "anchors" the nail to the nail bed.
The nail folds, which surround and protect the nail plate's margins, contribute to the overall structure but don't directly attach the nail to the nail bed itself. The nail bed's primary function is to support and provide a surface for the nail plate to adhere to as it grows.
