Chapter 11: Properties and Disorders of the Hair and Scalp TOPICS

MILADY’S PROFESSIONAL BARBERING COURSE MANAGEMENT GUIDE LESSON PLAN 11.0

1. Introduction 2. The Structure of Hair A. Description B. Hair Root and Hair Shaft C. Chemical Composition of Hair D. Hair Growth 3. Hair Analysis 4. Hair Loss 5. Disorders of the Scalp A. Common Disorders B. Staphylococci Infections 6. Disorders of the Hair A. Gray Hair B. Other Non-contagious Conditions

NOTES TO THE INSTRUCTOR It is vitally important that students understand the structure of hair because many of the judgments and decisions they will have to make about client services are dependent upon this information. As student barbers, they need to be able to analyze the hair and then suggest appropriate treatments and services; this cannot be achieved without a thorough understanding of the variables (texture, density, growth patterns, etc.) that are applicable from one individual to another. Students should be reminded that their professional responsibilities should include the goal to maintain their clients’ hair in a healthy condition through proper care and treatment.

STUDENT PREPARATION: Read Chapter 11: Properties and Disorders of the Hair and Scalp STUDENT MATERIALS

• Milady’s Standard Professional Barbering textbook • Milady’s Professional Barbering Student Workbook • Milady’s Professional Barbering Student CD-ROM • Writing materials • Materials and supplies for 3-D model project

LEARNING OBJECTIVES Upon completion of this lesson, students should be able to: 1. Name and describe the structures of the hair root. 2. List and describe the layers of the hair shaft. 3. Describe the structure of hair protein. 4. Describe the growth cycle of hair. 5. List the characteristics of hair important in hair analysis. 6. Identify different types of hair loss and treatments. 7. Identify common scalp disorders. 8. Identify common hair disorders.

216

© 2011 Milady, a part of Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 216216 55/31/10/31/10 110:45:550:45:55 AMAM ALLOTTED TIME: Four to six hours, depending on depth of study and range of activities. TEACHING AIDS

• Milady’s Standard Professional Barbering textbook • Milady’s Professional Barbering Instructor Slides • Whiteboard or chalkboard; dry-erase markers or chalk • CD/DVD player or overhead projector • Materials and supplies for 3-D model project

EDUCATOR REFERENCES

• Milady’s Standard Professional Barbering textbook • Milady’s Professional Barbering Course Management Guide

LESSON OUTLINE 1. Introduction A. Technical understanding of hair structure important to providing knowledgeable and professional service to clients. B. Professional responsibility: proper care and treatment to maintain hair in a healthy condition C. Trichology: the scientifi c study of hair, its disorders, and its care D. Hair protects the head from heat, cold, and injury and is used as adornment.

2. The Structure of Hair Activity 1: Distribute copies of Supplement 11.0 to students. Have students fi ll in the blanks as the topic is discussed. Refer to Supplement 11.1 for the answer key. A. Description 1. An appendage of the skin; a slender, thread-like outgrowth of the skin and scalp 2. Composed chiefl y of the protein keratin B. Hair Root and Hair Shaft 1. Hair root: portion of the hair beneath the skin surface, enclosed within the follicle 2. Hair shaft: portion of the hair extending above or beyond the skin surface 3. Structures of the hair root a. Main structures: follicle, bulb, dermal papilla, arrector pili muscle, and sebaceous glands. (Refer to textbook Figure 11-1.) b. Follicle: tube-like depression in the skin or scalp that encases the hair root 1. Extends down from the epidermis on an angle into the dermis; surrounds the dermal papilla 2. Bottom contains a fi nger-like projection called the papilla, from which new hair develops 3. Variance in follicle depth depending on the thickness and location of the skin 4. A follicle for every hair; more than one hair may grow from a single follicle. 5. Mouth of hair follicle: breeding places for germs and accumulation of sebum and dirt c. Hair bulb: thickened, club-shaped structure that forms the lower part of the hair root 1. Lower part of the hair bulb is hollow 2. Fits over and covers the dermal papilla; see textbook Figure 11-2. d. Dermal papilla: small, cone-shaped elevation at the base of the hair follicle 1. Fits into the hair bulb 2. Contains capillaries responsible for supplying oxygen/nutrients to the follicle epidermal tissue

217

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 217217 55/31/10/31/10 110:45:550:45:55 AMAM 3. Epidermal tissue surrounds papilla and forms the hair bulb. 4. Blood and nerve supply vital to growth and regeneration of the hair. 5. Nourishment reaches the hair bulb through the papilla. 6. Healthy papilla results in new hair growth. e. Sebaceous glands: small, sac-like structures with ducts attached to each hair follicle 1. Secrete sebum that gives hair luster and pliability 2. Factors associated with sebum production: (a) diet: health of the hair declines in the absence of necessary food elements; (b) emotional stress: linked with the health of the hair through the nervous system; (c) endocrine glands: hormonal in nature; infl uence the hair and other aspects of health; (d) drugs: hormones and certain medications may affect the hair adversely. f. Arrector pili: minute, involuntary muscle fi ber in skin attached to the hair follicle 1. Fear or cold causes contraction and makes hair stand up straight; “goose bumps.” 2. Eyelash and eyebrow hairs lack arrector pili muscles. 4. Structure of the hair shaft a. Layers of the hair shaft: cuticle, cortex, and medulla; see textbook Figure 11-3. b. Cuticle: outermost layer of hair, consisting of a single overlapping layer of transparent cells; see textbook Figure 11-4. 1. Scale-like cells point away from the scalp toward the hair ends. 2. Hair’s primary defense against damage is a healthy, compact cuticle layer. 3. Certain chemical solutions soften and raise scales to allow absorption by the cortex. c. Cortex: middle layer of the hair 1. Protein core that contains melanin pigment 2. About 90 percent of total hair weight comes from the cortex. 3. Protein structure provides strength, elasticity, and natural color to the hair. 4. Changes in hair during chemical services occur within the cortex. d. Medulla: innermost layer of the hair; composed of round cells 1. Male beard hair contains a medulla. 2. Medulla may be absent in very fi ne or naturally blonde hair found on the head. C. Chemical Composition of Hair 1. Introduction a. Hair is composed of protein that grows from cells originating within the hair follicle. b. Keratinization: maturation of cells as they fi ll with keratin, lose their nuclei, and die c. Hair shaft: a nonliving fi ber composed of keratinized protein (approximately 91 percent) 2. Protein: essential organic compounds necessary for life a. Made of long chains of amino acids b. Five elements make up amino acids in hair; these are the COHNS elements. c. Human hair: 51 percent carbon, 21 percent oxygen, 6 percent hydrogen, 17 percent nitrogen, and 5 percent sulfur d. Chemical composition varies with color. 1. Light hair: less carbon and hydrogen; more oxygen and sulfur. 2. Dark hair: more carbon; less oxygen and sulfur. 3. Nature of hair protein a. Peptide or end bonds: chemical bonds that join amino acids end-to-end in a defi nite order 1. Peptide bonds: strongest chemical bonds in the cortex 2. Join each amino acid to form a polypeptide chain 3. Most strength and elasticity of the hair is attributed to peptide bonds. 4. There is no way to reform broken peptide bonds.

218

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 218218 55/31/10/31/10 110:45:550:45:55 AMAM 5. Chemical processes and rough treatment of hair can break peptide bonds. 6. Polypeptide or polypeptide chain: long chain of amino acids joined by peptide bonds 7. Polypeptide chains intertwine to create a coil of protein called a helix; see textbook Figures 11-5 and 11-6. b. Side bonds or cross bonds of the hair cortex 1. Hair cortex contains millions of polypeptide chains cross-linked by side or cross bonds to form a ladder-like structure. 2. Side bonds: hydrogen, salt, and disulfi de bonds; account for hair strength and elasticity. See textbook Figure 11-7. c. Hydrogen bond: physical cross bond; easily broken by water or heat 1. Individual hydrogen bonds are weak but numerous. 2. Account for about one-third of hair’s overall strength 3. Add body to the hair 4. Help to keep parallel chains of polypeptides together 5. Also known as H-bonds 6. Water, dilute alkali, neutral, and acid solutions will break hydrogen bonds. 7. Drying and dilute acids will reform hydrogen bonds (see Table 11-2). d. Salt bond: physical cross bond that reacts to changes in pH 1. Account for one-third of hair’s total strength 2. Easily broken by strong acidic or alkaline solutions (Refer to textbook Table 11-2.) e. Disulfi de bond: covalent bond that joins sulfur atoms of two neighboring cysteine amino acids to create cystine 1. Stronger than hydrogen and salt bonds but fewer in number 2. Account for a third of the hair’s total strength (See textbook Table 11-2.) 3. Are not broken by heat or water; require chemical solutions to change or restructure 4. Also known as sulfur bonds, S-bonds, and cystine bonds 4. Hair Pigment a. Natural hair color: the result of melanin pigment found within the cortex b. Two types of melanin: eumelanin and pheomelanin 1. Eumelanin: provides brown and black color to hair 2. Pheomelanin: provides color ranges from red and ginger to yellow or light blonde tones c. Natural color: dependent on eumelanin/pheomelanin ratio; total number and size of granules d. Hair density varies with hair color. 1. Blond: 140,000 total hairs 2. Brown: 110,000 total hairs 3. Black: 108,000 total hairs 4. Red: 80,000 total hairs 5. Wave Pattern a. Wave pattern: refers to amount of movement in the hair strand b. Descriptions: straight, wavy, curly, or extremely curly c. Wave pattern results: genetics and racial background; all found in each racial or ethnic group; see textbook Figures 11-8 and 11-9. d. Hair shapes: cross-sectional view of a hair strand e. Hair may assume the shape, size, and direction of the follicle; no strict rule. 1. Straight hair: usually round 2. Wavy hair: usually oval 3. Extremely curly hair: usually almost fl at

219

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 219219 55/31/10/31/10 110:45:550:45:55 AMAM D. Hair Growth 1. Hair present all over the body except on the palms, soles, lips, and eyelids. 2. Three main types of hair; see textbook Figure 11-10. a. Vellus/lanugo: fi ne hair on cheeks, forehead, and the body; aids perspiration evaporation b. Primary terminal: short, thick hair that grows on the eyebrows and eyelashes c. Secondary terminal: long hair found on the scalp, beard, chest, back, and legs 3. Average growth of scalp hair: ½" per month 4. Growth: not increased by shaving, trimming, cutting, singeing, or ointment or oil application 5. Normal shedding a. Average loss: 75 to 100 hairs per day b. Eyebrow hairs and eyelashes: replaced every four to fi ve months 6. Growth patterns a. Working with hair’s natural growth pattern produces a more natural-looking haircut and style. b. Hair stream: hair that fl ows in the same direction; two streams fl owing in opposite directions form a natural part in the hair. c. Whorl: hair that forms in a circular or swirl pattern d. Cowlick: a tuft of hair that stands straight up 7. Growth cycles (See textbook Figure 11-11.) a. Anagen: growth phase 1. New hair produced 2. 90 percent of hair growing at one time 3. Lasts three to fi ve years b. Catagen: transition phase between growth and resting phases 1. Follicle shrinks, hair bulb disappears, and shrunken root end forms a rounded club. 2. Lasts from one to three weeks 3. Less than 1 percent of hair is in the catagen phase at any one time. c. Telogen: resting phase 1. Lasts for three to six months, until fully grown hair is shed 2. About 10 percent of scalp hair is in telogen phase at any one time. 3. Growth process repeats itself once every four to fi ve years. 8. Summary of growth cycle a. The new hair is formed by cell division from a growing point at the root around the papilla. b. The bulb loosens and separates from the papilla. c. The bulb moves upward in the follicle. d. The hair moves slowly to the surface, where it is shed. e. Barbering services include a variety of applications that benefi t from a barber’s ability to analyze the condition of his or her client’s hair; in addition to wave and growth patterns, barbers should be able to analyze the hair’s texture, density, porosity, and elasticity.

3. Hair Analysis A. Analysis is performed by observation, using the senses of sight, touch, hearing, and smell. 1. Sight: what the hair looks like (dry, oily, etc.) 2. Touch: what the hair feels like 3. Hearing: listen carefully to what clients say about their hair, products, etc. 4. Smell: certain scalp disorders create an odor; healthy hair and scalp are generally odor-free.

220

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 220220 55/31/10/31/10 110:45:550:45:55 AMAM B. Factors in Hair Analysis: texture, density, porosity, and elasticity; growth pattern; and condition 1. Hair texture: refers to the degree of coarseness or fi neness of individual hair strands a. Measures the diameter of the hair strand b. Classifi ed as coarse, medium, or fi ne 1. Coarse: largest diameter; stronger than fi ne hair; may require more processing time or stronger products. 2. Medium: most common; considered normal; does not usually pose special problems. 3. Fine: smallest diameter; generally more fragile; easier to process; more susceptible to damage. 4. Wiry hair: may be coarse, medium, or fi ne; has a hard, glassy fi nish. 5. Determine hair texture: feel a single dry strand by rolling it between two fi ngers. 2. Hair density: measures the amount of hair per square inch of scalp area a. Classifi ed as thick, average, or thin; or high, medium, or low density b. Average hair density: approximately 2,200 per square inch 3. Hair porosity: ability of the hair to absorb moisture a. Directly related to the condition of the cuticle b. Compact cuticle layer: more resistant to penetration; raised cuticle easily absorbs water. c. Classifi ed as moderate, poor, and porous; or average, low, and high porosity 1. Moderate or average: considered normal; no special problems; chemicals process as expected 2. High or porous: considered over-porous; absorbs liquids quickly and requires special care 3. Poor or low: considered resistant; absorbs least amount of moisture; may require more alkaline solution d. Porosity check: Hold strand of dry hair between fi ngers while sliding down toward scalp; 1. See textbook Figure 11-12. 2. Smooth, compact cuticle equals resistant; slight roughness equals porous; breakage equals over-porous. 4. Hair elasticity: ability of the hair to stretch and return to its original length without breaking a. Normal: springy, with a lustrous appearance b. Wet hair with normal elasticity can stretch up to 50 percent of original length without breaking. c. Elasticity test: gently tug a few strands of hair; see textbook Figure 11-13. d. Elasticity level: indication of cross-bond strength 1. Normal: holds curl from wet sets and permanent waves without excessive relaxing of the curl 2. Low or poor: brittle, breaks easily, and does not hold a curl; hair may be over-processed. Activity 2: Distribute an index card to each student, then have students partner with each other. Have students use the cards to record their fi ndings after analyzing each other’s hair texture, density, porosity, and elasticity. When the cards are completed, visit each pair of students and check their analysis.

4. Hair Loss A. Alopecia 1. Technical term for any type of abnormal hair loss; types include androgenic alopecia, alopecia areata, alopecia senilis, and alopecia syphilitica. a. Androgenic: hair loss occurring as a result of genetics, age, and hormonal changes 1. Causes shrinkage of terminal hair; converts it to vellus hair. See textbook Figure 11-14. 2. Can begin as early as the teens (prematura); frequently seen by age 40 3. Known as male pattern baldness in men; see textbook Figure 11-15.

221

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 221221 55/31/10/31/10 110:45:550:45:55 AMAM b. Areata: characterized by the sudden falling out of hair in round patches that create bald spots 1. May be an autoimmune disease; see textbook Figure 11-16. 2. May progress to total loss of scalp hair (totalis) or complete body hair loss (universalis) 3. Temporary alopecia areata: a result of anemia, scarlet fever, typhoid fever, nervous conditions, or malnutrition; refer clients with symptoms to a physician. c. Senilis: normal loss of scalp hair occurring in old age; loss of hair is permanent. d. Syphilitica: caused by syphilis; bald areas look moth-eaten; may affect beard and eyebrow areas 2. Treatments a. Minoxidil 1. Topical treatment applied to scalp twice a day 2. Non-prescription drug available for men and women 3. Two strengths: 2 percent for regular and 5 percent for extra strength. 4. No known negative side effects b. Finasteride 1. Oral prescription medication for men 2. Possible weight gain or loss of sexual function c. Surgical treatments: transplants or hair grafts are probably the most common permanent hair-replacement technique. Refer to textbook Chapter 16 for additional options.

5. Disorders of the Scalp A. Common Disorders 1. Pityriasis: dandruff; small, white scales appearing on scalp and hair; excessive production, shedding, and accumulation of surface cells; caused by a fungus called malassezia a. Pityriasis capitis simplex: classic dandruff, characterized by scalp irritation, large fl akes, and itchy scalp (Refer to textbook Figure 11-17a.) 1. Cause: sluggish scalp due to poor circulation, lack of nerve stimulation, emotional or glandular disturbances, improper diet, and poor personal hygiene 2. Treatments: use of mild or medicated shampoos, scalp massage or treatments, and antiseptic or medicated scalp ointments b. Pityriasis steatoides: more severe form; characterized by an accumulation of greasy or waxy scales mixed with sebum (Refer to textbook Figure 11-17b.) 1. Cause: excessive shedding of scales mixed with sebum; dandruff sticks to scalp in patches; causes itching and irritation; torn scales may cause bleeding 2. Medical treatment is advised. c. Contagion 1. Once thought to be contagious; newest research says it is not. 2. Should be treated as contagious 3. Common use of tools and implements is prohibited. 4. Barbers must practice approved sanitation and disinfection procedures before and after each client. 2. Tinea a. Medical term for ringworm 1. Caused by vegetable parasites such as fungi; highly contagious; easily transmitted 2. Characterized by itching, scales, and sometimes painful circular lesions 3. Starts with small, reddened patch of blisters that spread outward, then heal in the middle; cases should be referred to a physician. b. Tinea capitis: ringworm of the scalp; characterized by red papules at hair follicle openings; hair becomes brittle and breaks off; see textbook Figure 11-18.

222

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 222222 55/31/10/31/10 110:45:550:45:55 AMAM c. Tinea sycosis, also known as tinea barbae: fungal infection occurring over the bearded areas; characterized by small, round, slightly scaly, infl amed patches 1. Hard, lumpy swellings develop as parasites invade the hairs and follicles. 2. Severe cases: pustules form around hair follicles, rupture, and form crusts. 3. Hair becomes dry, breaks off, and falls out. 4. Highly contagious; medical treatment is required. d. Tinea favosa: also known as tinea favus or honeycomb ringworm; characterized by dry, yellowish, cup-like crusts on the scalp with a peculiar musty odor 1. Scars from favus are bald patches, pink or white, and shiny. 2. Highly contagious; should be referred to a physician 3. Animal parasitic infestations a. Pediculosis capitis: the infestation of the hair and scalp with head lice; see textbook Figures 11-19 and 11-20. 1. Head lice feed on the scalp and cause severe itching. 2. Transmitted through contact with infested hats, combs, brushes, and other personal items 3. Commercial products available for treatment of head lice. 4. Head lice can live off of the human body for up to 48 hours. 5. Disinfect all household and personal items to avoid re-infestation. 6. Cases of head lice should not be treated in the barbershop. 7. Thoroughly disinfect all tools, fi xtures, and furnishings. b. Scabies: highly contagious skin disease caused by the itch mite; characterized by vesicles or pustules caused by scratching affected areas (Refer to textbook Figure 11-21.) 1. Suspected cases should be referred to a physician for medical treatment. 2. Approved sanitation and disinfection procedures help to limit the spread of scabies. B. Staphylococci Infections 1. Sycosis vulgaris: chronic bacterial infection of the beard or mustache follicles; characterized by papules and pustules pierced by hairs, and tender, swollen, itchy skin. a. Transmitted by the use of unsanitary towels and implements b. Medical treatment is required. c. Do not confuse with tinea sycosis, caused by ringworm fungus. 2. Furuncle or boil: acute bacterial infection of a hair follicle, producing constant pain a. Infl ammatory process that produces a pustule perforated by a hair (Refer to textbook Figure 11-22.) b. Medical treatment is recommended. 3. Carbuncle: result of an acute, deep-seated bacterial infection in the subcutaneous tissue; similar to a furuncle, but larger; medical treatment is recommended. 4. Folliculitis: infl ammation of the follicle caused by bacteria or irritation a. Staphylococcus aureus and yeast: common bacterial causes of folliculitis b. Chemical exposure or mechanical irritation caused by improper shaving, hair breakage, or ingrown hairs are irritants that cause folliculitis (refer to textbook Figure 11-23). c. Accompanied by infl ammation and pus as a result of hair growing under the skin d. Treatments: drying up and disinfection of pustules; desensitization of the area 5. Pseudofolliculitis barbae: also referred to as razor bumps a. Resembles folliculitis, without the pus b. Caused by improper shaving or broken hair below the skin surface c. Bacteria may develop pus and folliculitis. d. Prevention 1. Shave in the direction of the hair growth; avoid close shaving. 2. Use electric razors or razors that cut hair above the skin. 3. Offer instruction in proper shaving techniques. 223

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 223223 55/31/10/31/10 110:45:550:45:55 AMAM e. Treatments 1. Preparations with salicylic acid break up impactions and kill bacteria. 2. Topical or oral antibiotics may be prescribed by a physician.

6. Disorders of the Hair A. Gray Hair 1. Canities: technical term for gray hair a. Due to loss of the hair’s natural melanin pigment in the cortical layer b. Gray hair is the same as pigmented hair. c. Gray hair grows out as gray hair; graying does not take place after the hair has grown. d. Types of canities 1. Congenital: exists at or before birth; occurs in albinos; occasionally with normal hair 2. Acquired: may be due to natural aging process, genetics, illness, etc., or may be premature 3. Ringed hair: alternating bands of gray and pigmented hair throughout the hair strand B. Other Non-contagious Conditions 1. Hypertrichosis or hirsuties: a condition of abnormal hair growth a. Characterized by terminal hair in areas where only vellus hair would normally grow b. Treatments: tweezing, depilatories, waxing, shaving, mechanical epilators, and electrolysis 2. Trichoptilosis: technical term for split ends; may be removed by cutting; see textbook Figure 11-24. 3. Trichorrhexis nodosa: technical term for knotted hair; nodular swellings along the hair shaft may be softened with conditioners or moisturizers. See textbook Figure 11-25. 4. Monilethrix: technical term for beaded hair; hair breaks easily between nodes; conditioning treatments recommended. See textbook Figure 11-26. 5. Fragilitas crinium: technical term for brittle hair; conditioning treatments recommended. Activity 3: Separate the class into groups of three or four students each, depending on the size of the class. Assign each group one of the following topics: structure of the hair root; cross- sectional view of the hair shaft; the nature of hair protein; disorders of the scalp; and disorders of the hair. Have the groups create 3-D models of their topic and then present the models to the class as a review prior to the chapter test.

SUMMARY/REVIEW: What did we learn and do today?

1. Named and described the structures of the hair. 2. Discussed and described the three layers of the hair shaft. 3. Described and discussed the structure of hair protein. 4. Discussed the characteristics of hair important in hair analysis. 5. Each student performed a hair analysis on a partner and recorded the evaluation. 6. Discussed and described the growth process of hair. 7. Described and identifi ed different types of hair loss. 8. Identifi ed common scalp disorders, their causes, and treatments. 9. Identifi ed common hair disorders and treatments. 10. Began 3-D model project (optional).

THEORY REVIEW QUESTIONS AND ANSWERS

1. Why is the study of hair important to barbers? Answer: So they will be able to provide knowledgeable and professional service to clients 2. What is the technical term for the study of hair? Answer: Trichology

224

97147_11_ch11_p216-240.indd 224 7/31/10 1:50:29 PM 3. What is the difference between the hair root and hair shaft? Answer: The hair root is that portion of the hair that lies below the skin surface; the hair shaft is that portion of the hair that extends beyond the skin surface. 4. List the structures of the hair root. Answer: Follicle, bulb, dermal papilla, arrector pili muscle, and sebaceous glands 5. Identify the layers of the hair shaft. Answer: Cuticle, cortex, and medulla 6. What are amino acids? Answer: Chemical units that make up protein 7. What are peptide bonds? What are they also known as? Answer: Chemical bonds that join amino acids together from end to end; also known as end bonds 8. List the side bonds in the hair. What are these bonds also known as? Answer: Hydrogen bonds, salt bonds, and disulfi de bonds; also known as cross bonds. 9. What are some ways in which peptide bonds can be broken? Answer: Through cutting, overstretching, or the use of strong acidic or alkaline solutions 10. In what ways can side bonds be broken? Answer: Hydrogen bonds can be broken with water, dilute alkali, neutral, and acid solutions. Salt bonds are broken by strong acidic or alkaline solutions. Disulfi de bonds are broken or restructured with chemical solutions. 11. What is melanin? Answer: Hair pigment 12. What is the defi nition of wave pattern? Answer: The amount of movement in the hair strand 13. What is meant by a hair stream, whorl, and cowlick? Answer: A hair stream is hair that fl ows in the same direction; a whorl is hair that forms in a circular or swirl pattern; and a cowlick is a tuft of hair that stands straight up. 14. What happens during the anagen, catagen, and telogen phases of hair growth, and how long do the phases last? Answer: The anagen phase is the growth phase when new hair is produced. It lasts three to fi ve years. The catagen phase is the transition phase between the growth and resting phases. In this phase, the follicle shrinks, the hair bulb disappears, and the shrunken root end forms a rounded club. It lasts from one to three weeks. The telogen phase is the resting phase and lasts for three to six months, until the fully grown hair is shed. The growth process repeats itself once every four to fi ve years. 15. What are the characteristics of hair used in hair analysis and what are their defi nitions? Answer: Texture, which refers to the degree of coarseness or fi neness of individual hair strands; density, which measures the amount of hair per square inch of scalp area; porosity, which is the ability of the hair to absorb moisture; and elasticity, which is the ability of the hair to stretch and return to its original shape 16. List and describe different types of hair loss. Answer: Androgenic alopecia is hair loss occurring as a result of genetics, age, and hormonal changes. Alopeica areata is the sudden falling out of hair in round patches that creates bald spots. Alopecia senilis is the normal loss of scalp hair occurring in old age. Alopecia syphilitica is caused by syphilis, and is characterized by bald areas that look moth-eaten. 17. What are the common disorders of the scalp discussed in the lesson, and what are their defi nitions? Answer: Pityriasis capitis simplex is classic dandruff. Pityriasis steatoides is a more severe form of pityriasis capitis. It is a greasy, waxy form of dandruff. Tinea capitis is ringworm of the scalp. Tinea sycosis is also known as barber’s itch and is a fungal infection that occurs over the bearded areas of the face. Tinea favosa is also known as tinea favus or honeycomb ringworm. It has a musty odor. Pediculosis capitis is an infestation of the hair and scalp with head lice. Scabies is a highly contagious skin disease caused by the itch mite.

225

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 225225 55/31/10/31/10 110:45:560:45:56 AMAM 18. What are the causes and characteristics of folliculitis and pseudofolliculitis? Answer: Folliculitis and pseudofolliculitis are infl ammations of the follicle caused by bacteria such as Staphylococcus aureus or yeast; by irritation caused by chemical exposure; or by mechanical irritation caused by improper shaving, hair breakage, or ingrown hairs. These irritants cause infl ammation and pus as a result of hair growing under the skin. Pseudofolliculitis barbae is also referred to as razor bumps and resembles folliculitis without the pus; it is generally accepted to be caused by ingrown hair. It is caused by improper shaving and/or broken hair below the skin surface that grows into the sides of the follicle, where bacteria may develop pus and folliculitis. 19. What is sycosis vulgaris? Answer: A chronic staphylococci bacterial infection of the beard and mustache follicles 20. What is a furuncle? Answer: A furuncle or boil is an acute bacterial infection of a hair follicle producing constant pain 21. What non-contagious disorders of the hair were discussed in this lesson and what are their defi nitions? Answer: Canities is the technical term for gray hair. There are two types: congenital and acquired. Hypertrichosis or hirsuties is a condition of abnormal hair growth, characterized by terminal hair in areas where only vellus hair would normally grow. Trichoptilosis is the technical term for split hair ends. Trichorrhexis nodosa is the technical term for knotted hair. It has nodular swellings along the hair shaft. Monilethrix is the technical term for beaded hair. The hair breaks easily between the nodes. Fragilitas crinium is the technical term for brittle hair.

ASSIGNMENTS

1. Read Chapter 12: Treatment of the Hair and Scalp. 2. Begin Workbook Chapter 12: Treatment of the Hair and Scalp; due date: ______.

226

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 226226 55/31/10/31/10 110:45:560:45:56 AMAM Textbook Chapter Review Questions and Answers Chapter 11: Properties and Disorders of the Hair and Scalp

1. Why is the study of hair important to the barber? So he or she will be able to provide knowledgeable and professional service to clients 2. Identify the technical term for the study of hair. Trichology 3. Describe the differences between the hair root and hair shaft. The hair root is that portion of the hair that lies below the skin surface; the hair shaft is that portion of the hair that extends beyond the skin surface. 4. List the structures of the hair root. The structures of the hair root are the follicle, bulb, dermal papilla, arrector pili muscle, and sebaceous glands. 5. Identify the layers of the hair shaft. The three main layers of the hair shaft are the cuticle, cortex, and medulla. 6. What are amino acids? Chemical units that make up protein 7. What are peptide bonds? Peptide bonds are chemical bonds that join amino acids together end-to-end; they are also known as end bonds. 8. List the side bonds in the hair. Hydrogen bonds, salt bonds, and disulfi de bonds 9. Identify ways in which peptide bonds and side bonds can be broken. Peptide bonds can be broken through cutting, over-stretching, or the use of strong acidic or alkaline solutions. Water, dilute alkali, neutral, and acid solutions will break hydrogen bonds. Salt bonds are broken by strong acidic or alkaline solutions, and disulfi de bonds are broken or restructured with chemical solutions. 10. What is melanin? Hair pigment 11. Defi ne wave pattern. Wave pattern is the amount of movement in the hair strand. 12. Defi ne hair stream, whorl, and cowlick. A hair stream is hair that fl ows in the same direction; a whorl is hair that forms in a circular or swirl pattern; and a cowlick is a tuft of hair that stands straight up. 13. Defi ne and explain the anagen, catagen, and telogen phases of hair growth. The anagen phase is the growth phase when new hair is produced. It lasts three to fi ve years. The catagen phase is the transition phase between the growth and resting phases. In this phase the follicle shrinks, the hair bulb disappears, and the shrunken root end forms a rounded club. It lasts from one to three weeks. The telogen phase is the resting phase and lasts for three to six months, until the fully-grown hair is shed. The growth process repeats itself once every four to fi ve years.

227

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 227227 55/31/10/31/10 110:45:560:45:56 AMAM 14. List and defi ne the characteristics of hair used in hair analysis. Texture refers to the degree of coarseness or fi neness of individual hair strands and is measured by the diameter of the hair strand. Density measures the amount of hair per square inch of scalp area. Porosity is the ability of the hair to absorb moisture. Elasticity is the ability of the hair to stretch and return to its original shape. 15. List and describe different types of hair loss. Androgenic alopecia is hair loss occurring as a result of genetics, age, and hormonal changes. Alopecia areata is the sudden falling out of hair in round patches that create bald spots and may lead to alopecia totalis or alopecia universalis. Alopecia senilis is the normal loss of scalp hair occurring in old age. Alopecia syphilitica is caused by syphilis and is characterized by bald areas that look moth-eaten. 16. List and describe common disorders of the scalp. Dandruff, vegetable parasitic infections, animal parasitic infestations, and staphylococci infections a) Pityriasis capitis simplex is classic dandruff characterized by scalp irritation, large fl akes, and an itchy scalp. It may be due to poor scalp circulation, lack of nerve stimulation, emotional or glandular disturbances, improper diet, or poor personal hygiene. b) Pityriasis steatoides, a more severe form of pityriasis capitis, is caused by excessive shedding of scales and an accumulation of greasy, waxy scales mixed with sebum. c) Tinea capitis is ringworm of the scalp, caused by a vegetable or plant parasite. It is characterized by red papules at hair follicle openings. d) Tinea favosa is also known as tinea favus or honeycomb ringworm. It is characterized by dry, yellowish, cup-like crusts on the scalp that have a peculiar, musty odor. It is highly contagious and medical treatment is required. e) Pediculosis capitis is an infestation of the hair and scalp with head lice. Head lice feed on the scalp and cause severe itching. Lice may be transmitted through the common use of personal items, combs, furnishings, and so forth. f) Scabies is a highly contagious skin disease caused by the itch mite. Scratching affected areas may cause vesicles and pustules. It is contagious and cases should be referred to a physician for medical treatment. 17. Explain the similarities and differences associated with folliculitis barbae and pseudofolliculitis barbae. Folliculitis and pseudofolliculitis are infl ammations of the follicle caused by bacteria or irritation. Staphylococcus aureus and yeast are common bacterial causes of folliculitis. Chemical exposure and mechanical irritation caused by improper shaving, hair breakage, or ingrown hairs are irritants that cause folliculitis and may be accompanied by infl ammation and pus as a result of hair growing under the skin. Pseudofolliculitis barbae, also referred to as razor bumps, resembles folliculitis without the pus. It is caused by improper shaving and/or broken hair below the skin surface that grows into the sides of the follicle, where bacteria may develop pus and folliculitis. 18. List and describe disorders of the hair. Canities is the technical term for gray hair. There are two types: congenital and acquired. Hypertrichosis or hirsuties is a condition of abnormal hair growth, characterized by terminal hair in areas where only vellus hair would normally grow. Trichoptilosis is the technical term for split hair ends. Trichorrhexis nodosa is the technical term for knotted hair. It has nodular swellings along the hair shaft. Monilethrix is the technical term for beaded hair. The hair breaks easily between the nodes. Fragilitas crinium is the technical term for brittle hair.

228

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 228228 55/31/10/31/10 110:45:560:45:56 AMAM Test—Chapter 11 PROPERTIES AND DISORDERS OF THE HAIR AND SCALP Read each statement carefully. Circle the letter that correctly completes each of the following statements. 1. The scientifi c study of hair, its disorders, and its care is called: a) dermatology c) mycology b) trichology d) physiology 2. The hair is a threadlike outgrowth of the skin present on the: a) palms c) scalp b) soles d) lips 3. The chief purpose of hair is to: a) keep the scalp oily c) keep the scalp dry b) protect and adorn d) keep dandruff in place 4. Hair is chiefl y composed of a horny substance called: a) hemoglobin c) keratin b) melanin d) calcium 5. Hard keratin is a substance composed of: a) minerals c) melanin b) protein d) chemicals 6. That portion of the hair found beneath the skin surface is called the: a) hair root c) hair shaft b) hair bulb d) hair papilla 7. The portion of the hair that extends beyond the skin surface is known as the: a) hair root c) hair shaft b) hair bulb d) hair follicle 8. The portion of the hair that is not enclosed within the follicle is the: a) hair root c) hair shaft b) hair bulb d) hair papilla 9. The main structures of the hair root are the follicle, the bulb, and the: a) dermal papilla c) arrector pili muscle b) sebaceous glands d) a, b, and c 10. A tube-like depression in the skin or scalp that encases the hair root is the: a) hair root c) hair shaft b) hair bulb d) hair follicle 11. The natural fl ow of the hair as it emerges from the scalp and slants in a particular direction is known as the: a) hair bend c) hair stream b) hair structure d) hair follicle

229

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 229229 55/31/10/31/10 110:45:560:45:56 AMAM 12. A club-shaped structure that forms the lower part of the hair root is the: a) hair papilla c) hair shaft b) hair bulb d) hair follicle 13. The structure that fi ts over the dermal papilla is the: a) hair root c) hair shaft b) hair bulb d) hair follicle 14. A small, cone-shaped elevation at the base of the hair follicle is called the: a) dermal papilla c) hair shaft b) hair bulb d) hair follicle 15. Nourishment reaches the hair bulb through the: a) dermal papilla c) hair shaft b) hair root d) hair follicle 16. Sac-like structures with ducts that are attached to each hair follicle are called: a) sudoriferous glands c) follicle glands b) sebaceous glands d) excretion glands 17. Glands that secrete sebum to the hair and scalp are called: a) sudoriferous glands c) sebaceous glands b) follicle glands d) excretion glands 18. Some factors that infl uence sebum production are: a) diet and blood circulation c) emotional disturbances and drugs b) stimulated endocrine glands d) a, b, and c 19. An involuntary muscle fi ber attached to the underside and base of the hair follicle is the: a) striated muscle c) erector pili muscle b) arrector pili muscle d) epicranius muscle 20. The three main layers of the hair shaft are the: a) cuticle, cortex, and medulla c) root, bulb, and dermal papilla b) follicle, root, and bulb d) follicle, root, and papilla 21. The outermost layer of the hair shaft is the: a) medulla c) hair shaft b) cortex d) cuticle 22. To penetrate the cuticle layer in order to reach the cortex, a solution must be: a) as acidic as the hair c) less alkaline than the hair b) more alkaline than the hair d) of a neutral pH 23. Changes that take place in the hair during chemical services occur within the: a) medulla c) cortex b) hair shaft d) cuticle

230

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 230230 55/31/10/31/10 110:45:560:45:56 AMAM 24. About 90 percent of the total weight of the hair can be traced to the: a) cortex c) medulla b) shaft d) cuticle 25. That portion of the hair that provides strength, elasticity, and natural color is the: a) medulla c) cortex b) hair shaft d) cuticle 26. The innermost layer of the hair shaft is the: a) medulla c) cortex b) hair shaft d) cuticle 27. Hair cells mature in the follicle through a process known as: a) cauterization c) keratinization b) dissemination d) propagation 28. Hair is made of approximately: a) 61 percent protein c) 81 percent protein b) 71 percent protein d) 91 percent protein 29. The elements found in human hair are carbon, oxygen, hydrogen, nitrogen, and: a) sulfur c) iron b) calcium d) glycerin 30. Proteins are made of long chains of chemical units known as: a) cells c) amino acids b) minerals d) calcium 31. Peptide bonds join amino acids: a) side by side c) diagonally b) end to end d) horizontally 32. Peptide bonds are also known as: a) end bonds c) H-bonds b) polypeptide chains d) S-bonds 33. End bonds are: a) salt bonds c) chemical bonds b) physical bonds d) hydrogen bonds 34. The strongest chemical bonds in the hair are the: a) peptide bonds c) H-bonds b) salt bonds d) S-bonds 35. Chains of joined amino acids are known as: a) amino chains c) chemical chains b) end chains d) polypeptide chains

231

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 231231 55/31/10/31/10 110:45:560:45:56 AMAM 36. Intertwined polypeptide chains create a: a) hypertrophy shape c) ladder shape b) helix shape d) heliotrope shape 37. Disulfi de, hydrogen, and salt bonds are types of: a) side bonds or cross bonds c) chemical bonds b) physical bonds d) peptide bonds 38. Approximately one-third of the hair’s strength is attributed to the: a) salt bonds c) hydrogen bonds b) disulfi de bonds d) a, b, and c 39. Once end bonds are broken, they can: a) be reformed with chemicals c) be fused back together b) never be reformed d) be reformed with conditioners 40. Disulfi de bonds create: a) chemical cross bonds c) neither a nor b b) cystine d) both a and b 41. The bonds that provide the hair with the greatest resistance to chemicals are the: a) salt bonds c) cross bonds b) disulfi de bonds d) hydrogen bonds 42. Disulfi de bonds may be changed with: a) distilled water c) moisturizing shampoo b) conditioners d) certain chemical solutions 43. A solution that will not reform disulfi de bonds is: a) an oxidizer c) hydrogen peroxide b) water d) a permanent wave neutralizer 44. Hydrogen bonds help to keep the parallel chains of polypeptides together and: a) add body to the hair c) take the place of salt bonds b) keep amino acids connected d) account for all the hair’s strength 45. Hydrogen bonds are: a) chemical bonds c) mineral bonds b) physical bonds d) end bonds 46. Water, dilute alkali, neutral, and acid solutions will: a) strengthen H-bonds c) break H-bonds b) increase H-bonds d) reform H-bonds 47. Drying and dilute acids will: a) weaken hydrogen bonds c) dilute hydrogen bonds b) reform hydrogen bonds d) break hydrogen bonds

232

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 232232 55/31/10/31/10 110:45:560:45:56 AMAM 48. The type of melanin that provides brown and black color to hair is: a) eumelanin c) dark melanin b) pheomelanin d) light melanin 49. The type of melanin that provides a range of hair color from red to light blonde tones is: a) eumelanin c) dark melanin b) pheomelanin d) light melanin 50. The amount of movement in the hair strand is described as the: a) texture c) wave pattern b) growth pattern d) elasticity 51. Hair growth that is not considered to be one of the three main types is: a) vellus hair c) secondary terminal hair b) primary terminal hair d) tertiary terminal hair 52. Hair grows an average of: a) ¼" per month c) ¾" per month b) ½" per month d) 1" per month 53. It is normal to lose an average of: a) 25 to 50 hairs per day c) 75 to 100 hairs per day b) 50 to 75 hairs per day d) 100 to 150 hairs per day 54. Hair that fl ows in the same direction is known as a: a) hair parting c) whorl b) hair stream d) cowlick 55. The hair growth pattern that forms in a circular or swirl pattern is called a: a) hair parting c) whorl b) hair stream d) cowlick 56. Hair that protrudes straight out from the scalp may be evidence of a: a) hair parting c) whorl b) hair stream d) cowlick 57. New hair is produced during the: a) anagen phase c) telogen phase b) catagen phase d) resting phase 58. The transition period between the growth and resting phases of a hair strand is the: a) anagen phase c) intermediate phase b) catagen phase d) telogen phase 59. The fi nal phase of the hair cycle that lasts until the fully grown hair is shed is called the: a) anagen phase c) intermediate phase b) catagen phase d) telogen phase

233

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 233233 55/31/10/31/10 110:45:560:45:56 AMAM 60. The anagen phase generally lasts from: a) one to three weeks c) three to fi ve years b) three to six months d) one to seven years 61. On average, the entire growth process of hair repeats itself once every: a) four or fi ve days c) four or fi ve months b) four or fi ve weeks d) four or fi ve years 62. To determine the hair’s texture, density, porosity, and elasticity, the barber performs a: a) hair critique c) hair test b) hair analysis d) strand test 63. The texture of hair that has the largest diameter is: a) fi ne hair c) coarse hair b) medium hair d) wiry hair 64. The term used to indicate the number of individual hair strands per square inch of scalp area is: a) density c) elasticity b) porosity d) texture 65. The ability of the hair to absorb moisture determines its: a) level of density c) level of elasticity b) level of porosity d) variation in texture 66. The ability of the hair to stretch and return to its original length without breaking is its: a) level of density c) level of elasticity b) level of porosity d) level of texture 67. Alopecia is the technical term for any abnormal type of: a) hair loss c) oil gland disorder b) skin infl ammation d) sweat gland disorder 68. Hair loss that occurs as a result of genetics, age, and hormonal changes is called: a) androgenic alopecia c) alopecia areata b) alopecia senilis d) alopecia syphilitica 69. Hair loss characterized by the sudden falling out of hair in round patches is called: a) androgenic alopecia c) alopecia areata b) alopecia senilis d) alopecia syphilitica 70. Two hair loss treatments known to stimulate hair growth are: a) minoxidil and fi nasteride c) minoxidil and bactericide b) minoxidil and fi nesse d) minoxidil and ultraviolet rays 71. Common scalp disorders include dandruff, fungal infections, animal parasitic infestations, and: a) diplococcal infections c) staphylococcal infections b) streptococcal infections d) pediculosis infestations

234

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 234234 55/31/10/31/10 110:45:560:45:56 AMAM 72. The technical term for dandruff is: a) alopecia c) pityriasis b) steatoma d) dermatitis 73. Small, white scales appearing on the scalp and hair is a sign of: a) dermatitis c) herpes simplex b) eczema d) pityriasis 74. Classic dandruff characterized by scalp irritation, fl akes, and an itchy scalp is known as: a) pityriasis steatoides c) psoriasis b) pityriasis capitis simplex d) dermatitis 75. Dandruff characterized by accumulated greasy or waxy scales mixed with sebum is: a) pityriasis steatoides c) eczema b) psoriasis d) pityriasis capitis simplex 76. Ringworm is an example of a: a) vegetable defi ciency disease c) non-contagious infection b) fungal infection d) systemic infection 77. Ringworm of the scalp is the common name for: a) tinea c) tinea capitis b) tinea favosa d) tinea sycosis 78. Ringworm of the bearded area, or tinea barbae, is technically known as: a) tinea c) tinea capitis b) tinea favosa d) tinea sycosis 79. Ringworm that is characterized by dry crusts on the scalp with a musty odor is: a) tinea c) tinea capitis b) tinea favosa d) tinea sycosis 80. Tinea is an infection at the opening of the: a) sweat glands c) blood vessels b) oil glands d) hair follicles 81. All forms of tinea are: a) non-treatable c) non-contagious b) contagious d) treatable by the barber 82. Pediculosis capitis is a condition caused by: a) the head louse c) scabies b) the itch mite d) ringworm 83. Scabies is an animal parasitic disease due to: a) ringworm c) dandruff b) the itch mite d) eczema

235

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 235235 55/31/10/31/10 110:45:560:45:56 AMAM 84. Pediculosis and scabies are: a) non-communicable c) contagious infestations b) not contagious d) treatable by the barber 85. Clients with tinea, pediculosis, or a scabies condition should be: a) treated by the barber c) allowed barbershop services b) referred to a physician d) shampooed before haircut services 86. Sycosis vulgaris, furuncles, and carbuncles are the result of a: a) diplococcal infection c) staphylococcal infection b) streptococcal infection d) pediculosis infestation 87. A chronic bacterial infection of the follicles in the beard and mustache areas is: a) tinea vulgaris c) tinea favosa b) sycosis vulgaris d) tinea capitis 88. The common term for a furuncle is: a) wart c) scar b) milia d) boil 89. Infl ammations of the follicle caused by bacteria or irritation may be signs of: a) folliculitis c) a or b b) pseudofolliculitis barbae d) neither a nor b 90. When the pigment is gone and air spaces develop, the hair appears to be: a) black c) red b) brown d) grey 91. The term that does not mean the development of excessive body or facial hair is: a) hypertrichosis c) trichoptilosis b) superfl uous hair d) hirsuties 92. Split hair ends is known as: a) congenital canities c) monilethrix b) trichoptilosis d) acquired canities 93. Beaded hair is technically known as: a) monilethrix c) trichoptilosis b) hypertrichosis d) fragilitas crinium 94. Brittle hair is technically known as: a) trichoptilosis c) hypertrichosis b) canities d) fragilitas crinium 95. Trichorrhexis nodosa is the technical term for: a) knotted hair c) beaded hair b) split hair ends d) brittle hair

236

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 236236 55/31/10/31/10 110:45:560:45:56 AMAM 96. The coloring pigment in the hair and skin is called: a) toner c) melanin b) keratin d) cystine 97. Razor bumps is a common name for: a) folliculitis c) pseudofolliculitis barbae b) psoriasis d) eczema 98. Long hair found on the scalp, beard, chest, back, and legs is: a) primary terminal hair c) tertiary terminal hair b) secondary terminal hair d) lanugo hair 99. The term that indicates the diameter of a hair strand is: a) hair density c) hair elasticity b) hair porosity d) hair texture 100. Hair loss occurring in old age is called: a) androgenic alopecia c) alopecia areata b) alopecia senilis d) alopecia syphilitica

237

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 237237 55/31/10/31/10 110:45:560:45:56 AMAM Answer Key—Chapter 11 PROPERTIES AND DISORDERS OF THE HAIR AND SCALP

1. b 21. d 41. b 61. d 81. b 2. c 22. b 42. d 62. b 82. a 3. b 23. c 43. b 63. c 83. b 4. c 24. a 44. a 64. a 84. c 5. b 25. c 45. b 65. b 85. b 6. a 26. a 46. c 66. c 86. c 7. c 27. c 47. b 67. a 87. b 8. c 28. d 48. a 68. a 88. d 9. d 29. a 49. b 69. c 89. c 10. d 30. c 50. c 70. a 90. d 11. c 31. b 51. d 71. c 91. c 12. b 32. a 52. b 72. c 92. b 13. b 33. c 53. c 73. d 93. a 14. a 34. a 54. b 74. b 94. d 15. a 35. d 55. c 75. a 95. a 16. b 36. b 56. d 76. b 96. c 17. c 37. a 57. a 77. c 97. c 18. d 38. d 58. b 78. d 98. b 19. b 39. b 59. d 79. b 99. d 20. a 40. d 60. c 80. d 100. b

238

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 238238 55/31/10/31/10 110:45:560:45:56 AMAM Supplement 11.0 STRUCTURE OF THE HAIR ROOT

239

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 239239 55/31/10/31/10 110:45:560:45:56 AMAM Supplement 11.1 STRUCTURE OF THE HAIR ROOT

240

997147_11_ch11_p216-240.indd7147_11_ch11_p216-240.indd 240240 55/31/10/31/10 110:45:570:45:57 AMAM