Lunula (anatomy)
Encyclopedia
The lunula, or lunulae (little moon in Latin
), is the crescent-shaped whitish area of the bed of a fingernail or toenail. The lunula is the visible part of the nail matrix (i.e. the root of the nail).
In humans, it appears by week 14 of gestation
, and has a primary structural role in defining the free edge of the distal nail plate (the part of the nail that grows outward).
.
It is half-moon-shaped, and has unique histologic features. Examinations concluded that the lunula was an area of loose dermis with lesser developed collagen bundles.
The lunula is most noticeable on the thumb, however, not everyone's lunula is visible. In some cases, the eponychium
may partially or completely cover the lunula.
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
), is the crescent-shaped whitish area of the bed of a fingernail or toenail. The lunula is the visible part of the nail matrix (i.e. the root of the nail).
In humans, it appears by week 14 of gestation
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
, and has a primary structural role in defining the free edge of the distal nail plate (the part of the nail that grows outward).
Appearance
It is located at the end of the nail (that is closest to the skin of the finger), but it still lies under the nail. It is not actually white but only appears so when it is seen through the nail. Outlining the nail matrix, the lunula is a very delicate part of the nail structure. If one damages the lunula, the nail will permanently be deformed. Even when the totality of the nail is removed, the lunula remains in place and is similar in appearance to another smaller fingernail embedded in the nail bedNail bed
Nail bed can refer to:* Bed of nails, a device sometimes used in meditation and physics demonstrations* Bed of nails tester, a device used to test printed circuit boards* Fingernail region also known as the "quick"...
.
It is half-moon-shaped, and has unique histologic features. Examinations concluded that the lunula was an area of loose dermis with lesser developed collagen bundles.
The lunula is most noticeable on the thumb, however, not everyone's lunula is visible. In some cases, the eponychium
Eponychium
In human anatomy, the eponychium [Greek epi + onychion ], also known as the cuticle, is the thickened layer of skin surrounding fingernails and toenails. Beneath the cuticle is a thin layer of a membrane known as the pterygium. The function is to protect the area between the nail and epidermis...
may partially or completely cover the lunula.