Nail apparatus and function Flashcards
1
Q
What is the Nail Matrix important for?
A
- responsible for formation of nail plate, by producing onychocytes
2
Q
What are characteristics of the Nail Plate?
A
- Onychocytes form the flat, square transparent nail plate
- Connective tissue fibres hold it to the nail bed
- Curvature of the nail relates to the shapre of the underlying distal phalanx
- Has three layers
3
Q
what are the three layers of the nail plate?
A
- Dorsal (upper) - only a few cell layers thick, but consists of hard keratin
- Imtermediate (middle) - thickest cell layer, consists of softer keratin
- Ventral (lower) - think cell layer,
4
Q
What is the Lunula?
A
- the visible portion of the nail matrix
- crescent shapred/whitish area of the nail plate
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5
Q
What is the function of the lateral nail folds?
A
- to provide cushioning to the cutaneous lateral margins of the nail
- Contributes to the adherence of the nail plate to the nail bed
- More prominent in toes than fingers
6
Q
What are the characteristics function of the proximal nail fold?
A
- Fold of skin lying above the nail matrix
- covers about 1/4 of the nail plate
- responsible for protecting part of the nail matrix
7
Q
What is the cuticle known as, and what are its characteristics?
A
- Eponychium
- Extends from the proximal nail fold and adheres to the dorsal part of the nail plate
- Composed of keratinocytes
- has a protective role, stops pathogens entering at base of the nail plate
8
Q
What is the nail bed and its functions?
A
- Extends from the distal margin of the lunula to the hyponychium
- Consists of epidermis and dermis
- longitudinal ridges increase surface area to increase passage of nutrients to the nail, e.g. keratin
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9
Q
What is the hyponychium?
A
- skin beneath the tip of the nail
- forms a seal that protects the nail bed
10
Q
what is the onychodermal band?
A
- the seal between the nail plate and the hyponychium
- grey-ish line
