1. Nail Structure and Growth
Spring Exam Review
Nail Structure and Growth

2. Natural Nail AKA onyx Made of keratin protein
Appendage (part of) the skin
Part of integumentary system
Has no sweat (sudoriferous) glands

3. Natural Nail Unit
Composed of the following parts: nail plate, nail bed, matrix, nail cuticle, eponychium, hyponychium, specialized ligaments, nail folds

4. Nail Plate Hardened plate that sits on and covers nail bed
Make of dead keratin cells
Is porous
Has about 100 layers
Free edge hangs over tip of finger and toe

5. Nail Bed Living skin under the nail plate Has many nerves
Attached to nail plate by bed epithelium
Bed epithelium- thin tissue that helps guide nail plate as it grows

6. Matrix Area where nail cells are formed
As long as it is healthy, nail will grow
Longer matrix makes a thicker nail
Visible part of matrix is the lunula

7. Nail Cuticle DEAD tissue attached to nail plate
Very sticky and hard to remove
Keeps germs from getting under nail plate

8. Eponychium LIVING skin at base of nail plate Covers matrix
We cannot cut it
Protects against bacteria

9. Hyponychium Skin between fingertip and free edge
Protectcts against bacteria

10. Specialized Ligaments
Tough band of fibrous tissue that connects nail bed and matrix to finger bone

11. Nail Folds Folds of skin around nail plate
Form nail grooves on sidewall
Sidewall AKA lateral nail fold

12. Nail Growth Average 1/10” per month Children’s faster- elderly slower
Faster in summer and pregnancy
Middle finger grows fastest
Thumb grows slowest
Fingernails grow faster than toenails
To replace fingernail= 4-6 months
To replace toenail= 9-12 months