1. Peggy McLemore Nail Structure & Growth
Chapter 21
Peggy McLemore
Nail Structure & Growth

2. The Nail Nail Technical term - onyx Appendage of the skin
Horny, translucent layer
Protective plate that protects the tips of fingers & toes
Part of the Integumentary system
The skin and its accessory organs, such as the oil and sweat glands, sensory receptors, hair & nails
Technical term - onyx

3. Composition Keratin Nail plate Healthy nail
protein that forms base of all horny tissue
Nail plate
contains no nerves or blood vessels
Healthy nail
whitish & translucent in appearance w/ pinkish color of nail bed showing through

4. Composition Nail porosity
water can pass through more easily than normal skin.
water content of nail is related to the humidity of the environment
10% to 30% water content

5. Composition Nail porosity
affects flexibility, less water content, more brittle the nail
ointment-based conditioner reduces loss of water in the nail

6. Nail Anatomy Six basic parts – figure 21-2,pg. 739 Nail bed
Matrix bed ( nail root )
Nail plate ( nail body )
Cuticular system
cuticle, eponychium, hyponychium
Nail folds
nail anatomy is the same in fingernails & toenails

7. Nail Bed Skin where nail body rests
Extends from lunula to just before free edge
Attached to nail plate by a thin layer of tissue called the bed epithelium
forces the plate to grow toward the end of the digit instead of growing straight up off the matrix bed
Supplied w/ many nerves

8. Matrix Bed Where nail is formed
Composed of matrix cells that produce the nail plate
Contains nerves, lymph, blood vessels to nourish nails

9. Matrix Bed Extends from under nail fold at base of nail plate
it can be seen as a whitish half-moon shape
called lunula - half moon
light color is caused by reflection of light where the matrix & connective tissue of the nail bed join
Growth affected by poor health, nail disorders or injury to nail matrix

10. Nail Plate Horny nail plate or nail body
Rests on & attached to nail bed
Formed by matrix cells
Constructed in layers
layers are visible when nail splits
Free edge extends over tip of finger or toe
It takes 6 months for a nail to grow from the root to the free edge. Toenails grow about 1 mm per month and take months to be completely replaced.

11. Cuticular System Crescent of toughened skin around base of nails
If normal loose & flexible
Seals area against foreign material & microorganisms
Helps prevent injury & infection

12. Cuticular System Eponychium Hyponychium
Extension of the cuticle at the base of nail a body that partly overlaps lunula
Hyponychium
The thickened corneum of the epidermis that lies beneath the free edge
Seals the free edge of the nail to the normal skin, preventing external moisture, bacteria or fungi getting under nail

13. Specialized ligaments
Ligament is a tough band of fibrous tissue that connects bones or holds an organ in place
attach the nail bed & matrix bed to underlying bone
located at the base of matrix & around edges of nail bed

14. Nail Folds Folds of normal skin surrounding nail plate
Form the nail grooves or slits or furrows of the sides of the nail
nail moves through the furrows as it grows
The mantle is the deep fold of skin in which the matrix bed ( nail root ) is lodged

15. Summary Nail is an appendage of the skin Technical term onyx Six parts
nail bed
matrix bed ( nail root )
nail plate ( nail plate )
cuticular system
specialized ligaments
nail folds

16. Questions Describe a normal healthy nail?
normal, healthy nail is firm & flexible, shiny, & pink in color. Its surface is smooth & unspotted, w/ no hollows or wavy ridges
What is the technical term for nail?
ONYX
What is the nail composed of?
mainly keratin, the same protein found in skin & hair

17. Questions Name the six basic parts of the nail?
nail bed, matrix bed, nail plate, cuticular system, specialized ligaments, & nail folds
What part of the nail contains the nerve & blood supply?
matrix bed contains nerves, lymph, & blood vessels to nourish the nail

18. Questions Explain how the nail grows.
normal nail grows forward, starting at the matrix & extending over the tip of the finger