Accessory Structures of the Skin: Nails

A nail is a hard, transparent protective plate. It is present on the dorsal surface of the distal portion of a finger or toe.

Its visible part is called the nail body or  plate composed of densely packed dead keratinocytes. Blood flow in the dermal capillaries of the nail bed — an epidermal layer below the nail, makes the nail body look pink, especially in light-skinned people.

The nail body extends at the distal end as a free edge. It is white-colored due to the absence of underlying capillaries. Beneath the free edge is the thickened skin region called the hyponychium.

The whitish crescent-shaped lunula or the little moon is near the proximal end of the nail body.

Skin folds onto the proximal end of the nail body forming the Eponychium or the cuticle. 

The nail root is buried in the skin, and proximal to it is the nail matrix consisting of mitotically active cells responsible for nail growth.