hair colors and henna

Question 1

three layers of hair:

Answer 1

1. cuticle (outer part)
2. the cortex (main body of hair shaft)
3. medulla (innermost, airspace)

Question 2

which part of the hair is thought to cause insulation (air pockets)?

Answer 2

the medulla

Question 3

the cortex contain natural moisture and pigment

Answer 3

true
it is visible through the translucent cuticle because the cuticle is like a window

Question 4

what is the cortex structure responsible for?

Answer 4

straightness, curliness, and elasticity

Question 5

the medulla varies in form and proportion

Answer 5

true

Question 6

the translucent scales of the cuticle are overlapping theyclose and open like a window angle

Answer 6

true

Question 7

which protein does hair consist of?

Answer 7

keratin
(18 amino acids bound to alpha helix, look like a coiled spring)
springs are held together by 3 types of bonds between chains & coilds

Question 8

what gives hair elasticity, bounce and strenght?

Answer 8

the springy shape.

even sraight hair has underlying coild structure

Question 9

what bonds are the strongest and what can break them?

Answer 9

• disulphide bonds are the strongest
• can be broken by perming, relaxing or bleaching

Question 10

what bonds are the weakest and easily broken?

Answer 10

hydrogen bonds and salt bonds

Question 11

how are the weakest bonds broken?

Answer 11

hydrogen bonds are stretched when wet

salt bonds are easily broken by weak acids or weak alkalis

Question 12

bonds that allow hair to be shaped into temporary style by setting or blow drying:

Answer 12

hydrogen and salt bonds

Question 13

texture is the diameter of a single hair

Answer 13

true
hair can be in any texture from very coarse to very fine and diameter is determined by genes

texture can also refer to the relative curliness or straightness
to the shape of cross-section

Question 14

the shape of cross-section that texture can refer to

Answer 14

• flat section: curly hair
• round section: straight hair

Question 15

hair properties

Answer 15

texture, porosity, hydroscopicity, elasticity

Question 16

what is porosity & hygroscopicity & elasticity

Answer 16

a measurment of the hair ability to absorbs moisture

hygroscopicity measures the hair ability to absorb water vabor

elasticity is the ability of the hair to strecth and return to its original shape

Question 17

hair in good condition has a compact smooth cuticle

Answer 17

true

Question 18

what does porosity depend on?

Answer 18

on the condition of the cuticle (how it opens and closes)

Question 19

lifted/opened/porous cuticle absorbs moisture and color fast and releases it quickly

Answer 19

true, also:
once the cuticle lifts or opens its no longer smooth. tangles when wet
dull when dry

Question 20

the older the hair the more porous it is

Answer 20

yes. plus depends on the length

Question 21

what opens the cuticle + increases porosity

Answer 21

heat chemicals sun general wear and tear

Question 22

what happens to hair when the atmosphere is more humid? (hygroscopicity)

Answer 22

hairbecomes more frizzy or drops. which makes life of blow dried hair shorter

Question 23

how to decrease hygroscopicity and prolong blow dry?

Answer 23

bt=y wearing mosse, gel, spray, lotions anything that prevents hair from absorbing moisture

Question 24

what does elasticity depend on?

Answer 24

resilience and strength of the bonds

Question 25

what happens to hair elasticity if the bonds are broken?

Answer 25

the hair will extend more but it will be less elastic

Question 26

The spring-like structure of the alpha helix allows dry hair to
stretch up to 30% of its length and return to its natural shape

Answer 26

tru

Question 27

acid flattens and closes the cuticle,
making hair shiny and smooth

Answer 27

true

Question 28

combination of pigments that natural hair is made of

Answer 28

eumelanin (black and brown)
phenomelanin (red and yellow)

Question 29

eumelanin is responsible for the level phenomelanin is responsible for the tone

Answer 29

yes

Question 30

tone is the natural color of the hair level just either makes the tone black or light

Answer 30

yes

Question 31

how is hair lightened/color lifted?

Answer 31

by oxidizing melanin in the cortex through a chemical reaction between oxygen and hydrogen peroxde
more oxygen = more color lifted

when u go darker u only add pigment

pigment molecules enter the cortex**

Question 32

The size of the molecule is one of the biggest factors in the
chemistry of going darker

Answer 32

yes. because pigment molecules ranges in size and dark is the largest (itseasier to go dark)

Question 33

By going darker gradually, you’ll be adding a healthy ratio of
light and dark pigments that will hold, like a sturdy brick wall,
and you’ll experience better results

Answer 33

true

Question 34

the lighter your starting point (for a dramatic change of 3 levels), the slower youll want to introduce color
why?

Answer 34

because each color change introduces porosity which means more damage

Question 35

types of hair colorants

Answer 35

1. temporary
2. semi permanent/direct dyes
3. semi permanent/oxidative dying systems
4. gradual coloring (heavy metals)
5. natural dyes

Question 36

temporary colorants

Answer 36

• only on cuticle
• leave in
• washed off

Question 37

direct dyes (semi permanent) advantage:

Answer 37

the melanin isnt bleached out its only covered with color

Question 38

direct dyes:

Answer 38

1. easily applied
2. fragrance may be added
3. color is gradually lost in 5-8 washes
4. strong color & long lasting
5. dark colorants do not contain H2O2

Question 39

The color obtained on the grey hair is different than the black
(pigmented) hair because of which the hairs are highlighted

Answer 39

in direct dyes