Chapter 5- Nail Structure and Growth

What is the water content of a healthy nail?

15 and 25 percent

A tough band of fibrous tissue that links bones or keeps an organ in place is called __________.

A ligament

Identify a function of the hyponychium.

It forms a protective barrier that keeps microorganisms from infecting the nail bed.

Which of the following statements is true of the nail plate?

It is the hardened keratin plate that rests on top of the nail bed.

Which of the following statements best describes the lunula?

It is the whitish, half-moon shape under the nail plate's base.

Identify a characteristic of a healthy nail.

It is translucent, and the beige or pinkish color of the nail bed shows through.

The __________ is part of the natural nail that contains nerves, blood vessels, and lymph to nourish cells that differentiate and become keratinized to form the nail plate.

Matrix

The __________ is the section of living skin that supports the nail plate as it extends toward the free edge.

Nail bed

Which of the following statements is true of nail growth rates?

Nail growth rates generally decrease with age.

The natural nail is technically called the __________.

Onyx

Identify a difference between the cuticle and the eponychium.

The cuticle is the dead tissue stuck to the nail plate, whereas the eponychium is the living skin under the proximal nail fold found at the nail plate's base covering the matrix area.

Which of the following statements is true of the growth of the nail plate?

The nail plate's growth is affected by nutrition, exercise, and overall health.

Identify a reason why cosmetologists should be knowledgeable about nail structure and growth.

Understanding natural nail structure and growth cycles prepares cosmetologists for advanced nail services.

What does a longer matrix lead to?

a thicker nail plate

The natural nail unit includes __________.

all parts of the finger from the tip to the first knuckle

Which of the following is NOT a natural nail shape?

almond

Ordinarily, complete nail plate replacement for a fingernail takes about __________.

four to six months

The natural nail unit is mainly made up of __________, which is the fiber-shaped protein found in skin and hair.

keratin

The nail matrix causes the nail plate to develop a series of slender grooves because __________.

parts of the nail matrix begin to permanently reduce production of new cells as a result of aging

The nail bed, nail fold, eponychium, paronychium, and hyponychium are collectively referred to as the __________.

perionychium

The __________ is the whole skin flap that covers the matrix, from the visible nail plate's edge to the first joint of the finger or toe.

proximal nail fold

Which of the following is NOT part of the perionychium?

the distal phalanx

Which of the following grows the fastest?

the nail of the middle finger

Cosmetologists should have a thorough understanding of nail structure and growth because __________.

they must be able to differentiate between the nail cuticle and the eponychium before performing nail services

The average rate of nail plate growth in an adult is about ______________.

⅒ to ⅛ inches (0.25 to 0.32 cm) per month.