HAIR by wanghonghx

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   Study of hair


 1. Protection from heat, cold, or injury
 2. Adornment for an AESTHETIC (beautiful, artistic) quality

What is Living Matter?
  It can grow
  Reproduce
  Respond to stimulation

Is Hair Alive?
    Only the cells of the hair bulb are alive
    The hair fiber (strand) is not alive


Hair Bulb
   Forms from a cluster of cells in the basal layer of epidermis
   EPIDERMIS = outermost skin layer
   Cluster of cells is called the primitive hair germ
   As the cluster seeks nourishment it pulls the basal layer down .
          forming a follicle

Hair Root
   Portion of the hair that is inside the hair follicle under
          the skin’s surface

Hair Fiber
   Also referred to as the shaft or strand
   Portion of hair that extends above the skin’s surface

   Tube-like pocket
   Called the Root Sheath
   Hair grows from it
   The shape of it will determine the shape of the hair shaft
          (Length of the hair)
   It also determines the diameter of the hair fiber

Three Follicle Shapes
   Round = straight or wavy hair
   Oval= straight or wavy hair
   Elliptical= curly/kinky hair


   As the primitive hair germ grows downward they join the
     dermal cells eventually becoming dermal papilla
   The papilla are filled with capillaries that supply nourishment
     to the cells

Germinal Matrix
   Area of the hair bulb where cell division takes place
   These cells will keratinize (to harden with the keratin protein)
    and form the three major layers of hair

The 3 Layers of a Hair Shaft
1 Medulla
2 Cortex
3 Cuticle

  Central core of the hair shaft
  Also called the pith
  Maybe absent in fine hair

   Inside of the second layer of hair
   Gives hair pigment and strength

   The outer covering of the hair shaft


Sebaceous glands
   Begin as bulges attached to the root sheath
   Produces sebum (oil), which is excreted through the follicles to
    the surface of the skin

Acid Mantle
   Sebum mixed with sweat
   Protects the cuticle
   Maintains acid balance of hair and skin

Arrector pilli Muscles
   Cells in the dermis that attach to the follicle just below the
    sebaceous gland
   Causes hair to stand on end when a person is scared or cold
   Also aids in secretion of sebum


   Process in which cells dry out and form keratin proteins
   Once this process occurs, the cells die
   When a cell fills with keratin the cytoplasm becomes thick like
    concrete setting up.
   Keratin protein is like concrete mix & the cytoplasm (cell fluid)
          has the moisture to cause it to set up.
   This is what actually kills the cell, its “guts” become “petrified”

   Made from the linking together of amino acids
   The cortex is made of a helix shaped protein strand
   Cortex is formed when amino acid chains wrap around each
     other forming protofibrils (beginning fibers)
   The protofibrils then twist around themselves to form
     microfibrils (small fibers).
   Microfibrils intertwine to form macrofibrils (large fibers)
   This twisting gives hair the ability to stretch, like a spring
   The cortex is then covered by cuticle scales, they are also

Proto = first
Micro = small
Macro = large


   Active or growing stage
   Each hair bulb has an attached root sheath
   This stage lasts 2 – 6 years
   Hair color is darker

   Transitional stage
   All cell division stops
   Lasts only a few months

   Resting stage
   Hair bulb has no attached root sheath
   Hair falls out
   Cell division begins again

Hair Growth Can Be Affected By…
   Illness
   Lack of vitamins
   Bad diet
   Disease
   Medication
   Each follicle grows at its own rate


Factors that Determine the Behavior of Hair
   Heredity = determines shape, color, and diameter
   Environment = humidity may cause hair to absorb moisture
     and cause the hair to frizz or go limp. Wind or sun may dry
     hair and cause damage.
   Products or Appliances = shampoos, curling irons, ect. may
     affect hair structure

Cuticle Characteristics
   The cuticle is the protective part of the hair and is composed of
     a harder protein than the cortex.
   If the hair fiber is composed of a higher percentage of cuticle
     than cortex, it will be more resistant perms and relaxers.


   Pigment found in plants that give them their color

  Pigment that gives humans their hair and skin color
  Found mainly in the cortex
  Made by cells called MELANOCYTES (-cyte = cell)

The Coloring Process
   Genes determine the number of melanocytes and the type of
    melanin produced
   Melanin is produced by melanocytes inside the hair bulb
   Melanocytes in the dermal papilli come together & form
    bundles of pigment protein called MELANOSOMES
   The size, type, & distribution of the melanosomes will
    determine the color of the hair

Two Types of Melanin
1 Eumelanin = brown/black color (eu- = true)
2 Pheomelanin = red color [ph(a)eo- = dusky, reddish brown]
   The amount and distribution of these melanins influence the
    resulting hair color.
   If pheomelanin is concentrated near the cuticle layer, the hair
    will appear more red
   Light hair has melanin only in the cortex
   Dark hair may have melanin in the cuticle layer
   Red hair also contains a pigment called TRICHOSIDERIN

   Total lack of pigmentation in the hair and skin
   True albinos lack ALL body pigment.
   This is why all true albinos have pink eyes.

Gray Hair
   Caused by reduced color pigment in the cortex
   Referred to Mottled Hair because of scattered white spots
    along the hair shaft
   Hair grows from the papilli with the gray color
   Natural aging process causes gray hair. It may also be caused
    by heredity, emotional condition, or illness.

Melanin in the Skin
  Melanin in skin and hair protect against UV rays
  When the skin is exposed to sunlight more melanin is
    produced, causing an increase in color = Suntan.
  People that live near the equator developed a higher melanin
    content in their skin and hair.
  White hair, which lacks melanin, has the highest risk of sun
    damage and may turn yellow.


   The degree of coarseness or fineness in the hair fiber

Hair Type
   Maybe fine, medium, or coarse
   Coarse hair has a rough texture
   Medium hair has the texture of cotton or is said to be wiry
   Fine hair has the texture of silk and is soft

Cuticle Damage
   Can cause hair to look dull, snag, or be hard to manage
   Test the cuticle by running your finger along the strand
   The more drag the more damage

Hair Density
   Judged by the number of active follicles per square inch on the
   Referred to as light, medium, or heavy
   Determines the amount of hair that should be parted and
     wrapped around a curler, perm rod, or curling iron


Hair Porosity
   The amount of moisture the hair is able to absorbed

Resistant Porosity
   Hair that is able to absorb the least amount of moisture
   Due to the closeness of cuticle layers

Average Porosity
   Hair with normal ability to absorb moisture
   Hair is considered to be in good condition

Extreme Porosity
   Hair damaged from chemical services or the environment

Uneven Porosity
   Combination of both porosities
   Partly extreme porosities, partly resistant porosity


   Ability to stretch & return to its original shape without breaking
   Also called Resiliency, Pliability, Buoyancy, or Springiness.
   Hair with normal elasticity is lively, able to spring back to its
     original state, & has a shiny appearance (LUSTER)
   Normal DRY hair can be stretched to 1/5 its original length.
   WET hair can be stretched 40-50% its length


   Every hair strand has 7 – 12 layers of cuticle scales protecting
    the cortex
   Healthy hair should have scales that lie flat
   Friction from combing and brushing can cause damage to the

Broken Hair (abraded hair)
   Caused by excessive stretching or traction, excessive chemical
    processes, sun exposure, or chlorine exposure
   Cuticle damaged called abraded cuticle
   Abrasion results from brushing and styling the hair, especially
    while wet
   Wet hair is more fragile
   Rubber bands, hair clips, and braids break the cuticle

Split Ends
   Technical term is FRAGILITIS CRINIUM, also called Brittle
     hair, or Trichoptilosis
   Begin as cracks in the cuticle, eventually reaching the cortex
     and splitting the hair entirely
   Can be temporarily sealed by protein reconditioning, this
     process will need to be performed repeatedly

  Excessive matting is called Pilica polonica
  Mass of hair strands tangled together in a mat that cannot be
  Cutting is the only solution
  Usually caused by excessive chemical hair lightening
  Maybe caused by repeated backcombing

   Called trichorrhexis nodosa or knotted hair
   Lumps or swelling along the hair shaft
   Lumps are broken or partially broken places on hair shaft
   Can be caused by poorly performed chemical services,
    mechanical damage, or by an inherited defect in keratin
   Physical knotting is caused by vigorous towel drying, or
    rubbing against a pillow

   Grayness or whiteness of the hair
   Occurs at or before birth in albinos and sometimes in people
    with normal hair
   Loss of pigment as a person ages
   Caused by extended illness, nervous strain, or heredity

Ringed Hair
   Alternating bands of gray and dark hair

   Abnormal coverage of hair on areas of the body where
    normally only lanugo hair appears
   Also referred to as hirsuties or superfluous hair
   Removal can be done by tweezing or electrolysis

  Beads or nodes formed on the hair shaft
  Breaks in hair occurs between the beads
  Treatments maybe given to improve the condition of the hair
  Mechanical damage results from the incorrect use of styling
  If a dryer is used too close to the hair or a curling iron left on
   too long the cortex may melt and the hair may become brittle
  Heat styling damage may include blistering and fracturing of
   the hair fiber


   Medical term pityriasis
   Overabundance of epithelial cells that have accumulated on the
   Treatments include using a medicated shampoo and the use of
    indirect high frequency treatments

Dry Dandruff
   Medical term pityriasis capitis simplex
   Dry epithelial cells attached to the scalp or hair
   Maybe itchy
   Caused by poor circulation, poor diet, uncleanliness, or
    emotional disturbance
   Treatment includes cleansing with mild shampoo and use an
    antiseptic lotion

Greasy Dandruff
   Pityriasis steatoides
   Epithelial cells combine with sebum
   Itchy, sticks to scalp in clusters
   Medical treatment advisable

   Tinea
   Red, circular patch of blisters
   Caused by a vegetable parasite = fungi
   Refer to doctor

Ringworm of the Scalp
   Tinea Capitis
   Enlarged open hair follicles that are surrounded by clusters of
    red spots, hair is likely to break
   Refer to doctor

Honeycomb Ringworm
   Favus
   Dry, yellow, encrusted area called scutula
   May have an odor
   Pink or white scars may result
   Refer to doctor

Itch Mite
    Scabies
    Red, watery vesicles or pus filled areas
    Caused by an animal parasite
    Refer to doctor

Head Lice
   Pediculosis capitis
   Infestation of lice causes itching and eventual infection
   Refer to doctor


Red = 90,000
Black = 108,000
Brown = 110,000
Blonde = 140,000

   There is an average of 1,000 hairs per square inch on the
    average head

Three Kinds of Hair
1 Lanugo
2 Vellus
3 Terminal

   Fine, silky, hair that covers the body before birth
   Shed shortly after birth
   Replaced by vellus

   Soft, fine hairs that cover the entire body

   Thick, strong, made of keratin
   Found in scalp, eyebrows/lashes, armpits, pubic area, & limbs
   In males, the facial & chest hair


   You are born with all of your hair follicles
   Terminal hair is the hair of the scalp and eyebrow
   Vellus hair covers most of the body and is not often visible to
    the naked eye
   Your follicles are predetermined to produce one of these hair
   40 – 100 strands of hair is the average daily hair loss

Androgenetic Hair Loss
   Alopecia (excessive hair loss) may be caused by a fungal or
    bacterial infection, or an inflammatory disease of the scalp
   Occurs in men and women
   If scalp looks abnormal refer to dermatologist
   If scalp is normal loss may be due to poor diet, drugs,
    emotional trauma, or other physiological changes
   Androgenetic alopecia is the most common, it is a combination
    of heredity, hormones, and age
   This causes a progressive shrinking of scalp follicles, this
    shortens the hairs growing cycle, eventually there is no growth
    at all

Recognizing Androgenetic Alopecia
  1. Ask about family history of hair loss.
  2. Ask if loss has been gradual or sudden.
  3. If loss was sudden and patchy, advise client to speak with a
  4. If the client is female, ask about crash diets, oral
     contraceptives, medications, vitamin deficiencies, and thyroid
  5. The hair loss process is a gradual conversion of terminal hair
     follicles to vellus-like follicles.
  6. Short, thin follicles are barely visible above the scalp surface;
     eventually no more hair is produced from these follicles
  7. Follicles are in the resting phase, resulting in less scalp
  8. The follicle does not change structure nor does the number of
     follicles change.
  9. In men, AKA male pattern baldness and usually progresses to a
     horseshoe shaped fringe.


  1. In women, it appears as a generalized thinning of hair all over
            the crown.
  2. It is extremely rare for women to go bald.
  3. Hold an index card at the scalp to help you see miniaturized
     hairs, if there are a lot than the client has androgenetic
  4. Part hair in the middle, if there is more scalp visible than
            normal indicates hair loss.
  5. Ask if the diameter of a ponytail has gotten smaller, if so it
           may be a sign of hair loss.
  6. Ask if there are many hairs left on a hairbrush after brushing
           once or many in the shower drain. Check for excessive
           shedding, if this is occurring refer to doctor.
  7. If male, ask if the bald spot of frontal hairline has increased.

Degrees of Hair Loss
   Pattern refers to the shape & location of the area with hair loss
   Density refers to how much hair is covering the scalp in the
    area of hair loss
   Because women experience only one pattern only density
    needs to be evaluated

Postpartum Alopecia
   Temporary hair loss after having a baby
   During pregnancy the hair stays in the anagen cycle, after
     childbirth the hair enters into the telogen cycle
   This hair loss is the result of the body’s hormone levels
     returning to normal

Alopecia Areata
   Sudden loss of hair in round or irregular patches
   Scalp is not inflamed
   Attributed to stress
   Confined to a few areas and may reverse itself in a few months

Telogen Effluvium
   Premature shedding of hair in the resting phase
   May result from child-birth, birth control, shock, drug intake,
    or fever
   Hair loss is reversed once the condition is corrected

Traumatic Alopecia
   Due to repetitive traction on the hair by pulling or twisting
   May also be caused by excessive application of permanent
    wave solution
   Condition can be reversed when trauma is stopped

Treatment of Androgenetic Alopecia
   FDA approved products that regrow hair or prevent loss
   Products that provide an ideal environment for possible hair
     regrowth or loss prevention
   Hair transplants, hair plugs, and scalp reductions. This may
     require many visits to a physician
   Wigs, toupees, hair additions, hair weaving
   Cosmetic hair thickeners that volumize hair, they do not grow

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