Chapter 9: Nail Structure and Growth

What is he average rate of nail growth per month on an adult?

1/10 of an inch per month

What is the average water content of the nail?

15-25%

After damage and return to a healthy matrix, how long does it take for a fingernail to grow back? How about a toenail?

4-6 months for a fingernail. 9 months- 1 year for a toenail.

What is the natural nail unit? Name its main parts.

All the main components of the natural nail. Consists of the nail plate, nail bed, matrix, nail cuticle, eponychium, hyponychium, specialized ligaments, nail folds

What is the natural nail and what is another name for it?

Also known as onyx. Hard protective plate composed mainly of keratin (like the protein found in skin and hair)

What other factors may influence how fast or slow a nail grows?

Children: grow faster Elderly: grow slower Pregnancy/hormone influxes: grow faster

What are some ways to improve the water content of the nail?

Coating plate with oil based nail conditioner/polish

Name the various nail shapes.

Concave , convex, square, angular, narrow, fan, trapezoid, olive, date, acorn, flat, arched, circumflex, arched, tubular, roofed

What is the nail cuticle?

Dead, colorless tissue attached to the natural nail plate. Comes from the skin that lies above the natural nail plate . Very sticky and designed to protect the nail bed from being contaminated.

What are the differences between the eponychium and the cuticle?

Eponychium is live tissue, cuticle is dead. Cuticle grows up from underside of nail plate and separates from the eponychium, creating a seal between it and the nail plate.

Which finger nail grows the fastest, and the slowest?

Fastest: nail of the middle finger Slowest: thumb

Which grow faster, toenails or fingernails?

Fingernails

Describe the appearance of a healthy nail.

Firm but flexible, shiny, smooth, up spotted, whitish/translucent, pinkish color of nail bed showing through

In which direction do healthy natural nails grow?

Forward from the matrix and extends of the finger.

Cosmetologists are permitted to nip and push back the cuticle, but only allowed to _________ the eponychium.

Gently push back

What is the nail plate? What is its purpose?

Hardened keratin plate that is formed by matrix cells. Relatively porous and contains the free edge. Serves to protect the nail bed.

Cosmetologists can only work on ________ nails and skin.

Healthy

Which body system are the nails part of?

Integumentary

What is the eponychium?

Living skin at the base of the nail area that covers matrix area.

What is the visible part of the matrix that extends from underneath the living skin, hidden under the eponychium?

Lunula

What are the folds of normal skin that surround the nail plate?

Nail folds

Do nail plates require oxygen? Why/why not? Do nail beds require oxygen? Why/why not?

Nail plates do not. Made of dead cells Nail beds do. Made up of live cells.

Can any procedure make nails thicker?

No. All depends on the matrix

Can nails perspire? Why/why not?

No. Does not contain sudoriferous glands

Are nails shed like hair? What would make a person shed a nail?

No. Only damage or disease to the matrix will make that happen

What is the free edge?

Part of the nail plate that extends over the top of the finger or toe

What factors can influence the growth and appearance of the nails?

Poor health, disorder/disease, matrix injury

Describe the nail bed and it's appearance. What is it purpose?

Portion of living skin that supports the nail plate as it grows. Pinkish appearance due to large amount of blood vessels. Contains many nerves and the bed epithelium.

The lower the water content of the nail, the more _____ it becomes.

Ridgid

What is another name for the lateral nail fold, which is the fold of skin overlapping the side of the nail?

Sidewall

What is the hyponychium?

Slightly thickened layer of skin that lies between fingertip and free edge. Protective barrier for nail bed

What are nail grooves?

Slits of furrows on the sidewall

What determines the shape of the nail?

The length, width and curvature of the matrix

What is the bed epithelium?

Thin layer of tissue attaching nail plate to the bed. Helps guide the plate along the bed as it grows.

Why are toenails thicker than fingernails?

Toenail matrix is longer than fingernail matrix

Describe the specialized ligaments of the nail.

Tough band of fibrous tissue to connect bones/organs in place. Attached at base of matrix and around wedges of nail bed

What is the matrix? Where is it located?

Where nail plate cells are formed. Composed of matrix cells, nerves, lymph, blood vessels. Extends from under the nail fold at base of nail plate.

Why is the lunula a half moon shape and a whitish color?

Whitish color caused by reflection of light off of the matrix. The lighter the color of the lunula shows the true color of the matrix.