Chapter 11
Which hair and scalp disorders cannot be treated in the salon.
All disorders of the scalp
What are the three phases of the hair growth cycle? What occurs during each phase?
Anagen phase- growth phase. New hit is produced. catagen phase- transition period between the growth and resting phases of the hair follicle. Signals end of the growth phase. telogen phase- the resting phase. The final phase in the hair growth cycle that lasts until the hair is fully grown and shed
What are the most common types of abnormal hair loss
Androgenic alopecia alopecia areata postpartum alopecia
Explain the process of keratinization
As newly formed cells mature they fill up with a fibrous protein called keratin. After they have filled with keratin the cells move upward lose their nucleus and die. By the time the hair shaft emerges from the scalp the calls of the hair completely keratinized and are no longer living
Name and describe the two types of melanin responsible for hair color
Eumelanin- provides natural dark brown to black color to hair pheomelanin- provides natural colors ranging from red and ginger to yellow and blonde tones
Name and describe the three layers of the hair shaft.
Hair cuticle- the outermost layer of the hair consists of a single over lapping layer of transparent scale-like cells that look like shingles on a roof cortex- middle layer of the hair a fibrous protein core formed by elongated cells containing melanin pigment Medulla- innermost layer of the hair that is composed of round cells offer absent in fine and naturally blond hair
Name and describe the five main structures of the hair root
Hair follicle- the tube like depression or pocket in the skin or scalp; contains the hair root Hair Bulb- lowest part of the hair strand; the thickened club shaped structure that forms the lower part of the hair root dermal papilla- small cone shaped elevation located at the base of the hair follicle that fits into the hair bulb. Contains the blood and nerve supply that provides the nutrients needed for hair growth. arrector pili muscle- small involuntary muscle in the base of the hair follicle. Strong emotions or a cold sensations cause it to contract. (Goose bumps) Sebaceous Glands- oil glands in the skin that are connected to the hair follicles. Secrete a fatty or an oily substance called sebum.
List and describe the three types of side bonds indicate whether they are strong or weak and why
Hydrogen bond- a weak physical cross link side bond easily broken by water or heat salt bond- a weak physical cross kind side bond between adjacent polypeptide chains. Disulfide bond- strong chemical side bond that joins the sulfur atoms of two neighboring cysteine amino acids to create one cystine. Joins together two polypeptide strands like rings on a ladder.
What are the only two hair loss treatments approved by the fda
Minoxidil and finasteride
What is the reason for normal daily hair loss
Natural result of the hairs growth cycle
Name the two main types of dandruff. Can either one be treated in the salon.
Pityriasis calorie simples and pityriasis steatoides. You should not perform a service on anyone who hair either of these conditions.
What four factors about the hair should be considered in the hair analysis
Texture density porosity elasticity
What are polypeptide chains
long chain of amino acids linked by peptide bonds
Name and describe the two types of hair and their location on the body
vellus hair- short fine unpigmented downy hair that appears on the body Terminal hair- long coarse pigmented hair found on the scalp legs arms and bodies of males and females