II. Anatomy
- Images
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
- Cuticle
- Intersection between nail plate and overlying skin at proximal nail
- Germinal matrix
- Root of the nail
- Forms nail plate from base of nail bed
- Distal matrix produces deeper nail plate
- Disruption may cause deep nail ridges
- Proximal matrix produces superficial nail plate
- Disruption may cause superficial Nail Pitting
- Eponychium
- Skin just proximal to cuticle
- Dorsal fold at proximal surface of nail
- Binds nail to underlying skin at proximal margin
-
Paronychial edge or Perionychium
- Lateral borders of nail
- Site of hangnails and Paronychia
- Hyponychium
- Area beneath free edge of nail
- Junction where nail bed meets tip of digit skin
- Nail Plate
- Hard and translucent
- Composed of dead keratin
- Surrounded by perionychium
- Nail Bed (Sterile Matrix)
- Adheres to underside nail with squamous epithelium
- Makes nail plate thicker and stronger
- Contains blood vessels and nerves
III. Physiology: General
- Nail is keratinized squamous cells
- Forms protective plate
- Prevents infection of underlying skin
- Enhances fingertip Sensation
- Nail acts as counterforce to fingertip
- Two Point Discrimination decreased when nail absent
- Attachment of nail to skin
- Proximal: Eponychium
- Distal: Anterior ligament, distal nail fold
- Lateral: Lateral nail folds
IV. Physiology: Nail Growth
- Normal Nail Growth
- Fingernails
- Grow 3 mm per month
- Require 6 months for complete re-growth
- Toenails
- Require 12-18 months to replace (2-3 times as long to re-grow as Fingernails)
- Fingernails
- Arrested Nail Growth
- Caused by any systemic illness
- Results in deep transverse grooves (Beau's Lines)
Images: Related links to external sites (from Bing)
Related Studies
| Concepts | Body Part, Organ, or Organ Component (T023) |
| SnomedCT | 24631007 |
| English | Eponychium, Eponychium (body structure) |
| Spanish | eponiquio (estructura corporal), eponiquio, eponychium |
Ontology: Structure of hyponychium (C0221998)
| Concepts | Body Part, Organ, or Organ Component (T023) |
| SnomedCT | 89699003 |
| English | Hyponychium, Structure of hyponychium (body structure), Structure of hyponychium |
| Spanish | estructura del hiponiquio (estructura corporal), estructura del hiponiquio, hiponiquio, hyponychium |
Ontology: Structure of nail of finger (C0222001)
| Definition (NCI_CDISC) | The nail at the end of a finger. (NCI) |
| Definition (NCI) | The nail at the end of a finger. |
| Concepts | Body Part, Organ, or Organ Component (T023) |
| MSH | D009262 |
| SnomedCT | 400133005, 91456000 |
| HL7 | FINGN, NAILF |
| Portuguese | Unhas das Mãos |
| Spanish | Uñas de las Manos, estructura de uña de dedo de la mano (estructura corporal), estructura de la uña de un dedo de la mano (estructura corporal), estructura de la uña de un dedo de la mano, estructura de uña de dedo de la mano, uña de dedo de la mano |
| French | Ongles des doigts |
| German | Fingernägel |
| English | Finger nail, Nail plate of finger, Nails of fingers, Finger nails, Set of nails of fingers, fingernail, fingernails, FINGERNAIL, Fingernail, Nail of finger, Structure of nail of finger (body structure), Structure of nail of finger, Nail of finger, NOS, Finger Nail, Fingernails, Nail, Finger |
| Italian | Unghie delle dita delle mani |
| Norwegian | Fingernegler |
| Czech | nehty na rukou |
| Dutch | Vingernagels |
Ontology: Structure of nail of toe (C0222007)
| Definition (NCI_CDISC) | A thin, horny translucent plate covering the end of each toe. (NCI) |
| Definition (NCI) | A thin, horny translucent plate covering the end of each toe. |
| Concepts | Body Part, Organ, or Organ Component (T023) |
| MSH | D009262 |
| SnomedCT | 76578001 |
| HL7 | TOEN, NAILT |
| LNC | LP30554-7, MTHU015074 |
| French | Ongles des doigts de pied, Ongles des orteils |
| Portuguese | Unhas dos Pés |
| Spanish | Uñas de los Pies, estructura de la uña del dedo del pie, estructura de uña de dedo del pie (estructura corporal), estructura de la uña del dedo del pie (estructura corporal), estructura de uña de dedo del pie, uña del dedo del pie, uña de dedo del pie, uña del pie |
| German | Zehennägel |
| English | Set of nails of toes, Toe nail, Toe nails, Nail plate of toe, Nails of toes, toenail, toenails, TOENAIL, Nail of toe, Toenail, Structure of nail of toe (body structure), Structure of nail of toe, Nail of toe, NOS, Toe Nail, Toenails, Nail, Toe |
| Italian | Unghie delle dita dei piedi |
| Norwegian | Tånegler |
| Czech | nehty na nohou |
| Dutch | Teennagels |
Ontology: Eponychium of finger (C0930791)
| Concepts | Body Part, Organ, or Organ Component (T023) |
| English | Finger eponychium, Eponychium of finger, Cuticle of finger, finger cuticle, eponychium of finger, cuticles finger |
Ontology: Eponychium of toe (C0930793)
| Concepts | Body Part, Organ, or Organ Component (T023) |
| English | Cuticle of toe, Eponychium of toe, Toe eponychium |
