Lunula ( anatomy ) - wikipedia Lunula ( anatomy ) For other uses, see Lunula. Lunula The lunula is the white crescent - shaped area of a finger. Details Part of Fingernail or toenail Identifiers Latin lunula TA A16. 0.01. 005 TH H3. 12.00. 3.02006 FMA 77858 Anatomical terminology ( edit on Wikidata ) The lunula, or lunulae ( pl. ) ( from Latin, meaning ' little moon ' ), is the crescent - shaped whitish area of the bed of a fingernail or toenail. The lunula is the visible part of 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 ). 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 be permanently 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 bed. In most cases, 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. It appears whitish because a thickened underlying stratum basale obscures the underlying blood vessels. The lunula is most noticeable on the thumb ; however, not everyone 's lunulae are visible. In some cases, the eponychium may partially or completely cover the lunula. See also Nail Nail disease References Jump up ^ Guglielmi, Giuseppe ; Kuijk, Cornelis Van ; Genant, Harry K ( 2001 ). `` Fundamentals of hand and wrist imaging ''. ISBN 978 - 3 - 540 - 67854 - 0. Skin and related structures Skin Epidermis Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale Basement membrane Basal keratinocyte Lamina lucida Lamina densa Dermis Papillary Dermal papillae Reticular Subcutaneous tissue Panniculus / Pannus ( Panniculus adiposus Panniculus carnosus ) Membranous layer Loose connective tissue Superficial fascia Adnexa Skin glands Sweat glands : Apocrine sweat gland Eccrine sweat gland Sebaceous Hair Root sheath Outer root sheath Inner root sheath Henle 's layer Huxley 's layer Hair shaft Cuticle Cortex Medulla Bulb with matrix cells Hair follicle Muscle Arrector pili muscle Pilosebaceous unit Hair sebaceous gland Nail Nail matrix Nail plate Lunula Eponychium Paronychium Hyponychium Retrieved from `` https://en.wikipedia.org/w/index.php?title=Lunula_(anatomy)&oldid=832967200 '' Categories : Nail anatomy Hidden categories : Pages with unresolved properties Talk About Wikipedia Български Español Français Galego Italiano Lëtzebuergesch Nederlands Polski Português Edit links This page was last edited on 28 March 2018, at 23 : 09. About Wikipedia

Question: what's the white part of your nail called
Answer: The lunula, or lunulae (pl.)