The nail organ is an integral ingredient of the digital tip. The is a highly versatile tool that protects the fingertip, contributes come tactile sensation by acting as a counterforce to the fingertip pad, and aids in peripheral thermoregulation via glomus bodies in the pond bed and matrix. <1, 2> due to the fact that of its kind and functionality, abnormalities that the nail unit result in functional and cosmetic issues. The structures that define and produce the pond (nail plate) include the procession (sterile and germinal), the proximal pond fold, the eponychium, the paronychium, and the hyponychium (see the images below). Collectively, the nail bed (sterile matrix), pond fold, eponychium, paronychium, and hyponychium are described as the perionychium.

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Nail surface ar anatomy.
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pond anatomy.

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The nail plate increase from the proximal nail fold and is bordered top top either next by the lateral pond folds (paronychium). The nail plate is created of hard, keratinized, squamous cells that room loosely adherent to germinal matrix but strongly attached to the sterile matrix. <2> The nail fold, the many proximal facet of the perionychium, is written of a dorsal roof and also a ventral floor. That is found around 15 mm distal to the distal interphalangeal joint (DIP). <3, 4>


The dorsal roof rests over the forming nail, and also the ventral floor lies beneath the nail, automatically distal to the insertion of the extensor tendons. The ventral floor is the website of the germinal matrix and is responsible because that 90% of pond production. The dorsal roof that the pond fold plays a role in real estate cells the impart shine to the nail. The skin proximal to the pond that covers the pond fold is the eponychium. The organization distal come the eponychium in call with the pond represents the cuticle.

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Extending indigenous proximal come distal top top the pond is a half-moon shame white arc recognized as the lunula (see the picture below). The lunula is the distal extent of the germinal matrix. <4> This characteristic color readjust is as result of the persistence of nail cell nuclei in the germinal matrix; distal come this location, nuclei are absent, and the nail is transparent. <2> The area that the pond bed distal to the lunula is the sterile matrix. This is a second site of pond production and also is tightly adherent come the pond plate and the periosteum that the distal phalanx.


Nail surface ar anatomy.

A junction is formed in between the sterile matrix and also the fingertip skin beneath the nail margin. This area is referred to as the hyponychium. This an ar is susceptible to contamination from eco-friendly interactions. A keratin plug acts as a mechanical obstacle to protect against infectious inoculation. Likewise found within this keratin plug room polymorphonuclear leukocytes and also lymphocytes contributing one immunologic obstacle to the mechanical one established by the keratin plug. <2>


The arterial blood it is provided to the perionychium originates from the terminal branches the the radial and ulnar appropriate palmar (volar) digital arteries. This vessels originate proximal come the metacarpophalangeal share from the common palmar digital arteries. The suitable palmar digital arteries branch proximal to the dip joint and give off a branch that travels dorsal come the emboldened joint, providing the superficial arcade that feeds the pond fold and proximal matrix. <3>