Chapter 11 Review

What are polypeptide chains?

A long chain of amino acids linked by peptide bonds.

Name and describe the two types of melanin responsible for natural hair color.

Eumelanin provides natural dark brown to black color. Pheomelanin provides natural colors ranging from red to blond.

List and describe the three types of side bonds. Indicate whether the are strong or weak and why.

Hydrogen bonds, weak bond broken by water or heat. Salt bond, weak bond broken by strong alkaline or acidic solution. Disulfide bond, strong, broken by permanent waves and chemical hair relaxers that alter the shape of hair.

Explain the process of keratinization.

Newly formed cells mature, they fill up with a fibrous protein called keratin. The hair shaft that emerges is a nonliving fiber composed of keratinized protein.

What are the two main types of dandruff? Can either one be treated in the salon?

Pityriasis capitis simplex and Pityriasis steatoides. Neither should be treated in a salon.

Name and describe the two types of hair and their locations on the body.

Vellus hair is short, fine, unpigmented hair in places such as forehead, eyelids, etc. Terminal hair is long, coarse, pigmented hair found on the scalp, legs, arms, etc.

What are the three phases of the hair growth cycle? What occurs during each phase?

Anagen phase, new hair is produced. Catagen phase, transition period. Telogen phase, resting phase.

Name are the most common types of abnormal hair loss?

Androgenic alopecia, alopecia areata, postpartum alopecia.

What is the reason for normal daily hair loss?

Result of the anagen, catagen, and telogen phases of the hairs growth cycle.

Name and describe the three layers of the hair shaft.

Hair cuticle, is the outermost layer of the hair. The cortex is the middle layer of the hair. The medulla is the innermost layer of the hair and is composed of round cells.

Name and describe the five main structures of the hair root.

Hair follicle, tube-like depression or pocket in the skin or scalp that contains the hair root. Hair bulb, lowest part of the hair strand. Dermal papilla, small, cone shaped elevation located at the base of the hair follicle that fits into the hair bulb. The arrector pili muscle is the small, involuntary muscle in the base of the hair follicle. Sebaceous glands are the oil glands in the skin that are connected to the hair follicles.

What are the only hair loss treatments approved by the FDA?

Minoxidil and finasteride.

Which hair and scalp disorders cannot be treated in the salon?

Pityriasis, tinea, scabies, pediculous capitis and staphylococci infections.

What four factors about the hair should be considered in a hair analysis?

Texture, density, porosity, and elasticity.