© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Chapter 9 Nail Structure and Growth

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Why study Nail Structure and Growth Understanding structure and growth allows you to expertly groom, strengthen, and beautify nails. It will better prepare you for advanced nail treatments. It is important to know the difference between the nail cuticle and the eponychium before the service.

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. The Nail The natural nail also known as onyx is the hard protective composed mainly of keratin. It is an appendage of the skin and part of the integumentary system. A normal nail is flexible but firm, with a shiny, smooth and with no ridges, pits, or splits. Healthy nails are whitish and translucent in appearance, with a pinkish color of the nail bed showing though. A healthy nail contains between 15-25% water and is effected by the humidity in environment. Water directly effects the nail’s flexiblity.

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Nail Anatomy: Major Parts Nail plate (nail body) Free edge Nail bed Matrix bed (nail root) Lunula Cuticle Eponychium Hyponychium Specialized ligaments Nail folds

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Nail Plate A hardened keratin plate that sits on and covers the nail bed. The most visible and functional part of the nail unit. The free edge is the part of the nail plate that extends over the tip of the finger or toe.

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Nail Bed The portion if living skin that supports the nail plate containing the blood vessels and nerves. The nail bed is attached to the nail bed by a thin layer of skin called the bed epithelium.

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Matrix Bed Where the nail plate cells are formed: blood and lymph, and nerves nourish nail bed. Shaped of nail bed is determined by shape and width of matrix Healthy matrix = healthy ­­­­­nail bed

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Lunula Visible part of matrix Whitish, half-moon shape at base of nail Color caused by reflection of light off matrix surface. Some are hidden under eponychium.eponychium

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Cuticle Dead, colorless tissues attached to the natural nail plate. Seals the space between the natural nail plate and the living skin. Prevents entry of microorganisms and foreign material helps avoid injury and infection.

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Eponychium The living skin at base of nail plate covering matrix Cannot be trimmed or cut by nail technician

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Hyponychium Slightly thickened layer of skin under the free edge. Forms a protective barrier from foreign material and infection.

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Specialized Ligaments Tough bands of fibrous tissue that connect bones or hold an organ in place Attach the nail bed and matrix bed to underlying bone Located at base of matrix and around edges of nail bed

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Nail Folds Folds of normal skin that surround the nail plate. Folds form the nail grooves which are slits on the side wall. Also known as Lateral nail fold fold of skin that overlapping the side of the nail.

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Nail Structure

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Nail Growth Process A normal nail grows forward from the matrix extending over the tip of finger or toe. They grow in a variety of shapes. Length, width, and curvature if the matrix determines the length, width, curvatures of the nail plate. Toenails are thicker and harder than fingernails because the matrix in toenails are longer. Average nail growth is 1/10 of an inch a month.

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Many factors affect growth: Age is a factor; children’s nail grows faster than adults while the elderly grow slowest. Seasons affect growth; nails grow faster in the summer than in the winter. Pregnancy affects growth due to hormonal changes in the body. The middle finger nail grows faster and the thumb grows slowest. Nail Growth Process (continued)

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Various Nail Shapes

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Nail Malformation Disease, injury or infection occurs in the matrix, the shape or the thickness of the nail plate can change. This is generally why a person’s nail will shed. After an injury to the nail with shedding the nail may grow back healthy as long as matrix is healthy and undamaged. If the matrix remains in good condition, a normal fingernail will be replaced in 4 to 6 months, a toenail in 9 to 12 months.

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. Summary and Review What is the technical term for the nail? What protein is in the nail plate? Describe the appearance of a normal, healthy nail. Name the basic parts of the nail unit. Explain the difference between the nail plate and the nail bed.

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. What part of the nail unit contains the nerves, lymph, and blood vessels? What is the difference between the cuticle and the eponychium? Why are cosmetologists not allowed to cut the skin around the base of the nail plate? What three things can affect the growth of the nail plate? Summary and Review (continued)

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. BED EPITHELIUM Thin layer of tissue that attaches the nail plate and the nail bed. EPONYCHIUM Living skin at the base of the natural nail plate that covers the matrix area. FREE EDGE Part of the nail plate that extends over the tip of the finger or toe. HYPONYCHIUM Slightly thickened layer of skin that lies between the fingertip and the free edge of the natural nail plate. VOCAB LIST CHAPTER 9 NAIL STRUCTURE

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. LIGAMENT Tough band of fibrous tissue that connects bones or holds an organ in place. LUNULA Visible part of the matrix that extends from underneath the living skin; it is whitish, half-moon shape at the base of the nail. MATRIX Area where the mail plate cells are formed; this area is composed of matrix cells that produce the nail plate. NAIL BED Portion of the living skin that supports the nail plate as it grows toward the free edge. VOCAB LIST CHAPTER 9 NAIL STRUCTURE

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. NAIL CUTICLE Dead, colorless tissue attached to the natural nail plate. NAIL FOLDS Folds of normal skin that surround the natural nail plate. NAIL PLATE Hardened keratin plate that sits on and covers the natural nail bed. It is the most visible and functional part of the natural nail unit. VOCAB LIST CHAPTER 9 NAIL STRUCTURE

© Copyright 2012 Milady, a part of Cengage Learning. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. NATURAL NAIL Also known as onyx; the hard protective plate is composed mainly of keratin, the same fibrous protein found in skin and hair. The keratin in natural nail is harder than in skin and hair. NATURAL NAIL UNIT Composed of several major parts of the fingernail including the nail plate, nail bed, matrix, cuticle, eponychium, hyponychium, specialized ligaments, and nail fold. Together, all of these parts form the nail unit. SIDE WALL Also known as lateral nail fold; the fold of skin overlapping the side of the nail. VOCAB LIST CHAPTER 9 NAIL STRUCTURE