2. © 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

3. © 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. Objectives Describe the structure and composition of nails. Discuss how nails grow.

4. © 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 translucent, protective plate that protects the tips of the fingers and toes. Onyx –the technical term for nail

5. © 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. Composition of the Nail

6. © 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. Keratin Keratin - The same protein found in skin and hair is also found in nails.

7. © 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 Porosity Nail porosity - Water can pass through the nail more easily than through normal skin. Water content of the nail is related to the humidity of the environment. A nail has 15 to 25 percent water content. Water affects flexibility. - Less water content = more brittle nail. Oil-based conditioner reduces water loss.

8. © 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. Healthy Nail Healthy nail - Whitish and translucent in appearance, with the pinkish color of the nail bed showing through.

9. © 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

10. © 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 (Nail Body) Nail Plate – The visible nail area. The most visible and functional part of the nail unit. Rests on/slides across nail bed. Constructed in layers

11. © 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. Free Edge Free edge – Part of the nail that extends past the skin.

12. © 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 Nail Bed – The skin the nail sits on. Supports nail plate as it grows toward free edge Extends from lunula to just before free edge Attached to nail plate Supplied with many nerves

13. © 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 (Nail Root) Matrix - Generates cells that make the nail. Composed of matrix cells that produce nail plate Contains nerves, lymph, blood vessels to nourish nails Extends from under nail fold at base of nail plate Injury to matrix or poor health affects nail growth

14. © 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 Lunula – Whitened half moon shape at the base of the nail. Visible part of matrix Color caused by reflection of light off matrix surface. Some are hidden under eponychium. eponychium

15. © 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 Cuticle – The overlapping skin around the nail. Dead, colorless tissue attached to nail plate from underside of skin that lies above natural nail plate Loose and flexible; difficult to remove from nail plate Seals area against foreign material and microorganisms Helps prevent injury and infection

16. © 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 Eponychium – Live skin that lies at the base of the nail plate covering the matrix. Cannot be trimmed or cut by nail technician

17. © 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 Hyponychium – Slightly thickened skin that lies between the fingertip and the free edge. Protective barrier that seals the free edge, preventing external moisture, bacteria, or fungi from getting under the nail

18. © 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 to underlying bone Located at base of matrix and around edges of nail bed Posterior Ligament Anterior Ligament

19. © 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 surrounding nail plate Form nail grooves on which the nail moves as it grows

20. © 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

21. © 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 Growth is affected by nutrition, general health, and exercise. Nails grow forward, starting at matrix and extending over fingertip. Nails grow in a variety of shapes. Average growth is 1/10 of an inch per month. Growth is faster in summer than winter. Children’s nails grow faster than adults’ nails.

22. © 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. Middle fingernail grows fastest. Thumbnail grows slowest. Toenails grow slower than fingernails. Nails are not shed automatically like hair is. Nail Growth Process (continued)

23. © 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 can affect the formation of nails. 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.

24. © 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

25. © 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 is the technical term for the nail? Onyx

26. © 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 protein is in the nail plate? Keratin

27. © 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. Describe the appearance of a normal, healthy nail. Whitish and translucent in appearance, with the pinkish color of the nail bed showing through.

28. © 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. Name the basic parts of the nail unit. Nail Bed Matrix Nail Plate Cuticle Eponychium Hyponychium Specialized Ligaments Nail Folds

29. © 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? The Matrix

30. © 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 is the difference between the cuticle and the eponychium? The cuticle is the dead, colorless tissue attached to the nail plate. The eponychium is the living skin at the base of the nail plate covering the matrix area.

31. © 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 are cosmetologists not allowed to cut the skin around the base of the nail plate? The eponychium is the living skin at the base of the nail plate covering the matrix area.

32. © 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 three things can affect the growth of the nail plate? The growth of the nail plate is affected by nutrition, exercise, and a person’s general health.

33. © 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. Congratulations! You have completed one unit of study toward course completion.