| A | B |
| The scientific study of the hair, its diseases, and care is called | trichology |
| The two parts of a mature hair strand are the hair shaft and | hair root |
| The portion of hair that projects above the skin is the | hair shaft |
| The follicle, bulb, papilla, arrector pili muscle, and sebaceous glands are the main structures of the | hair root |
| The tubelike depression or pocket in the skin or scalp that contains the hair root is the | follicle |
| Hair follicles are not found on the palms of the hands or the | soles of the feet |
| The follicle extends downward from the epidermis, where it surrounds the | dermal papilla |
| The lowest area or part of the hair strand is the | hair bulb |
| A small, cone-shaped area at the base of the hair follicle that fits into the hair bulb is the | dermial papilla |
| A tiny, involuntary muscle fiber inserted in the base of the hair follicle is the | arrector pili |
| The oil glands of the skin connected to the hair follicles are | sebaceous glands |
| An oily substance secreted from the sebaceous glands is | sebum |
| The overlapping layer of hair with transparent, scalelike cells is the | cuticle |
| The three main layers of the hair shaft are the cuticle, medulla, and | cortex |
| Swelling the hair raises the cuticle layer and allows for | penetration |
| For chemicals to penetrate a healthy cuticle hair layer, they must | have an alkaline pH |
| The fibrous protein core of the hair, formed by elongated cells containing melanin pigment, is the | cortex layer |
| The medulla is the innermost layer of the hair and is composed of | round cells |
| Hair is composed of a protein that grows from cells originated within the | hair follicle |
| The process whereby living cells mature and begin their journey up the hair shaft is | keratinization |
| The five main elements that make up the chemical composition of human hair are carbon, oxygen, hydrogen, and | nitrogen and sulfur |
| The chemical bonds that hold together the amino acid molecules are | peptide bond |
| An end bond is also known as a | peptide bond |
| When peptide bonds hold together a very long chain of amino acids, it is called a | polypeptide chain |
| The three types of cross-links that form the bonds between the polypeptide chains are hydrogen bonds, salt bonds, and | disulfide bonds |
| A weak type of physical side bond that is easily broken by water or heat is a | hydrogen bond |
| A salt bond is easily broken with the use of | strong alkaline or acidic solutions |
| Bonds that must be chemically separated are | disulfide bonds |
| hydrogen chemical hair relaxers break disulfide bonds and during rinsing convert them to | lanthionine bonds |
| The natural hair pigment found inthe cortex layer of the hair is | melanin |
| Two different types of melanin are eumelanin and | pheomelanin |
| Natural wave patterns are the result of | genetics |
| Asians tend to have | extremely straight hair |
| Extremely curly hair grows | in long twisted spirals |
| To help minimize tangles in extremely curly hair when washing, you should use | a detangling rinse |
| Extremely curly hair may often break or knot easily due to | low elasticity |
| Four important factors to consider in hair analysis are texture and porosity | elasticity and density |
| The thickness or diameter of the individual hair strand is the | hair texture |
| Hair texture is classified as | coarse, medium, or fine |
| The measurement of individual hair strands on one square inch of the scalp is | hair density |
| The ability of the hair to absorb water or oil is | porosity |
| Chemical services performed on hair with low porosity require | more alkaline solutions |
| Hair with high porosity is often the result of | overprocessing |
| The ability of the hair to stretch and return without breaking is | elasticity |
| Wet hair with normal elasticity will stretch up to | 50 percent |
| When shaping and styling hair, consider the hair's | natural growth pattern |
| Dry hair and scalp can be caused by | inactive sebaceous glands |
| Oily scalp and hair can be treated by properly shampooing with | normalizing shampoo |
| Hair that is not pigmented and almost never has a medulla is | vellus |
| Long, soft hair found on the scalp, legs, arms, and bodies of males and females is | terminal |
| The phases of hair growth are anagen, catagen, and | telogen |
| The growth phase where new hair is produced is | anagen |
| The average growth of healthy scalp hair is | one inch per month |
| The final or resting phase in the hair growth cycle is | telogen stage |
| In general, the cross sections of curly hair can be | oval |
| The term used to identify abnormal hair loss is | alopecia |
| The sudden falling out of hair in round patches or baldness in spots is called | alopecia areata |
| Two products approved by the FDA to stimulate hair growth and allowed for sale in the United States are | minoxidil and finasteride |
| The technical term used to describe gray hair is | canities |
| A variety of canities, characterized by alternating bands of gray and pigmented hair, is | ringed hair |
| A condition of abnormal hair growth on areas of the body is | hypertrichosis |
| Trichorrhexis nodosa is characterized by brittleness of the hair and the formation of | swellings along the hair shaft |
| The technical term used to describe beaded hair is | monilethrix |
| The medical term for dandruff is | pityriasis |
| The medical term used to describe a fungal organism characterized by itching, scales, and painful circular lesions is | tinea |
| The type of fungal infection characterized by red papules at the opening of the hair follicles is | tinea capitis |
| A highly contagious skin disease caused by a mite parasite is | scabies |
| An acute localized bacterial infection of the hair follicle that produces constant pain is | a furuncle |
| An inflammation of the subcutaneous tissue caused by staphylococci is | a carbuncle |
| The spread of diseases can be prevented by practicing approved | sanitation and disinfection procedures |