Chapter 11- Properties of the hair and scalp Flashcards
Disorders of the hair
-Canities-technical term for gray hair
-Ringed hair-alternating bands of gray and pigmented hair throughout the length of the hair strand.
-Hypertrichosis-condition of abnormal hair growth
-Trichoptilosis-technical term for split-ends
-Trichorrhexis nodosa-technical term for knotted hair
-Monilethrix-technical term for bleached hair
-Fragilitas crinium-technical term for brittle hair
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Postpartum Alopecia
Temporary hair loss experienced at the end of pregnancy
Alopecia Areata
Autoimmune disorder that cause the affected hair follicles to be mistakenly attacked by a persons own immune system
-affects 5 million people in the untied states
-small, round, smooth bald patch on the scalp and or total hair loss called “Alopecia totals”
*Complete body hair loss-Alopecia Universalis
Androgenic Alopecia
Hair loss is characterized by miniaturization of terminal hair that is converted into vellus hair.
-Teens to age 40 affected
-By 35 years of age almost 40% of men and women have hair loss
-Affects millions of men and women in the United States.
Alopecia
“Abnormal hair loss”
1.Androgenic alopcia
2.Alopecia areata
3.Postpartum alopecia
4.Postpartum alopecia
(most common types)
Telogen Phase
-Known as the resting phase, is the final phase in the hair cycle and lasts until the fully grown hair is shed.
-Less than 10% of the hair on your head is in the telogen phase.
-The entire growth cycle repeats itself once every 4-5 years
Catagen Phase
-is the brief transition period between the growth and resting phases of a hair follicle
-the follicle canal shrinks and detaches from the dermal papilla-during this stage
-last one-two week/during this phase
Anagen Phase
“Growth phase”
~New hair is produced~
-rapidly between 15-30 years old
-slows down after 50 years old
-90% of scalp hair is growing in the anagen phase at anytime
Terminal hair
Long, coarse, pigmented hair found on the scalp, legs, arms, and bodies of males and females
Vellus hair
“Lanugo Hair”
-Short, fine, unpigmented, and downy hair that appears on the body
Wave pattern/Cross sections
Straight hair-round cross-section
Wavy or curly hair- oval to round cross section
Extremely curly hair-elliptical cross section
Wave pattern
-Refers to the shape of the hair strand
1.straight
2.wavy
3.curly
4.extreamely curly
Pheomelanin
is the lighter pigment that provides natural colors ranging from red and ginger to yellow and blond tones
Eumelanin
provides natural dark brown to black color to the hair and is the dark pigment predominant in black and brunette hair
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Melanin
are the tiny grains of pigment in the cortex that gives natural color to the hair
Lanthionine bonds
-Hydroxide chemical hair relaxers break disulfide bonds and then convert them to- lanthionine bonds- when the relaxer is rinsed form the hair
Disulfide bond
-a strong, chemical, side bond that is very different from the physical side bond of a hydrogen bond or salt bond
*far fewer disulfide bonds than hydrogen or salt bonds, disulfide bonds are so much stronger
-make up 1/3 of hairs overall strength
* not broken by water
Cysteine “cystine”
The disulfide bond joins the sulfur stoms of two neighboring Cysteine-amino acids to create (one) Cystine
Salt bond
-also a weak, physical, cross-linked side bond between adjacent polypeptide chains
-depends on the PH
-easily broken by (strong alkaline and acidic solution)
-even though they are weak bonds, there are so many they account for about 1/3 of the hairs overall strength
Trichology
The scientific study of the hair and its disease and care.
-Trichos (hair)
-Ology (study of)
Hair root
Is the part of the hair located below the surface of the epidermis (outer layer of the skin)
Hair shaft
It the portion of the hair that projects above the epidermis
“Five main structures of the hair root”
1.Hair follicle
2.Hair bulb
3.Dermal papilla
4.Arrector pili muscle
5.Sebaceous glands (oil)
Hair follicle
Is the tube like depression or pocket in the skin or scalp that contains the hair root.
*sometimes more than one hair will grow from a single follicle
Hair Bulb
-is the lowest part of the hair strand
-thick, club shaped structure, at the lower part of the hair root
-fits over and covers the dermal papilla
Dermal Papilla
“Mother”
-is a small cone-shaped elevation located at the base of the hair follicle that fits into the hair bulb
-contains blood and nerve supply-provides nutrients needed for hair growth
Arrector Pili Muscle
“Goose bumps”
-is the small, involuntary muscle in the base of the hair follicle.
-strong emotions or cold sensation cause the muscle to contract
-this causes what referred to as goose bumps
Sebaceous Glands
-are the oil glands in the skin that are connected to the hair follicles
-the sebaceous glands secrete a fatty or an oily substance called sebum
-sebum-lubricates the skin
Sebum
The sebaceous glands secrete a fatty of an oily substance called sebum
-Lubrication for the skin
Hair Cuticle
-is the outermost layer of the hair.
-single overlapping layer of transparent, scale-like cells that look like shingles on a roof
-cuticle layer provides a barrier that protects, the inner ,structure of the hair as it lies tightly against the cortex
-responsible for creating the shine and the smooth, silky feel of healthy hair
~A healthy cuticle layer protects the hair from penetration and prevents damage to hair fiber. Oxidation hair-colors, permanent waving solution, and chemical hair relaxers must have an alkaline PH to penetrate the cuticle layer because a high Ph swells the cuticle and causes it to lift and expose the cortex
Cortex
-Is the middle layer of the hair
-Fibrous protein core formed by elongated cells containing melanin pigment
-90% of the total weight of hair comes from the cortex
-Elasticity and natural color-results in the unique protein structures in the cortex
-Changes involve-hair coloring, relaxing, thermal styling, -perms, wet setting, within the cortex
Medulla
-The inner most layer of the hair
-Very fine and naturally blond hair will entirely lack a medulla
-Thick and coarse hair will contain a medulla
Male beard hair contains a medulla
-The medulla is not involved in salon services.
Keratinization
Hair is composed of protein that grows from cells originating within the hair follicle. This is where the hair begins.
*As soon as these living cells form.
-they begin their journey upwards through the hair follicle
-This is the maturing process.
Keratin
-Newly formed cells mature, they fill up with a fibrous protein called keratin
-Once filled with keratin, the cells move upward, lose their nucleus and die.
-Once hair shaft emerges from the scalp, the hair is completely keratinized and no longer living.
-Hair shaft that emerges is a nonliving fiber composed of keratinized protein
COHNS Elements
90% protein
-Made of long chains of amino acids
-The major elements that make up hair are the following
1.Carbon 2.Oxygen 3.Hydrogen 4.Nitrogen 5.Sulfur
*These five elements are also found in the skin and nails
1.Carbon 51%
2.Oxygen 21%
3.Hydrogen6%
4.Nitrogen 17%
5.Sulfur 5%
(each hair strand)
Amino Acids
Proteins are made of long chains of amino acids units that are joined together end-to-end like “Pop beads”
Peptide bond
The strong, chemical bond that joins amino acids is a peptide bond also known as “end bond”
Polypeptide chain
A long chain of amino acids linkked by peptide bonds are called a “polypeptide chain”
Proteins
Are long, coiled complex polypeptides made of amino acids
Helix
-The spiral shape of a coiled protein
*This is created when the polypeptide chains intertwine with each other
Side bonds
-That link the polypeptide chains together and are responsible for the extreme strength and elasticity of human hair
*Essential to wet setting, thermal styling, permanent waving, and chemical hair relaxing
Hydrogen bond
-Is a weak, physical, cross-link side bond that is easily broken by water or heat.
-broken by wetting the hair
-allows the hair to be stretched
-bonds reform when the hair dries
Pityriasis Capitis simplex
Is the technical term for classic dandruff that is characterized by scalp irritation, large flakes, and itchy scalp
Pityriasis Steatoides
This is a severe case of dandruff that is characterized by an accumulation of greasy, wavy scales mixed with sebum that stick to the scalp in crust.
Tinea
Technical term for a ringworm.
(itching, scales, and sometimes painful circular lesions)
-this is caused by a fungal organism and not a parasite
-highly contagious, and can spread
Tinea Favosa
-Dry, sulfur yellow, cuplike crusts on the scalp (called Scutula)
Scutula- has a distinctive odor
Tinea Barbae
-Superficial fungal infection, affects the beard, and areas of the face, and neck or around the scalp
(do not preform a service on a client who is infected)
Pediculosis Capitis
-The infestation of the hair and scalp with head lice
*As these parasites begin to feed on the scalp it begins to itch
Furuncle
-Boil, an acute localized bacterial infection of the hair follicle that produces constant pain
-Constant pain, and pustule perforated by a hair.
Carbuncle
-an inflammation of the subcutaneous tissue caused by (staph) Staphylococci
(similar to a furuncle but is larger)
Follliculitis
_infection of the hair follicle frequently caused by Staphylococcus or other bacteria.
-small, white headed pimple seen around one or more follicles
(referred to as barbae itch or hot tub folliculitits)
Hair Analysis
-Performed by observation using the sense of Sight, Touch, Sound and Smell
-The four main factors to consider in the hair analysis are Texture, Density, Porosity, and elasticity
Hair Texture
is the thickness or diameter of the individual hair strand
-Coarse, Medium, and Fine
Coarse hair
-Has the largest diameter
-Stronger than fine hair
-more resistant to processing than medium or fine hair
-requires more processing time
Medium hair
-Most common hair texture
-does not pose any special problems or concern
Fine hair
-Smallest diameter
-more fragile
-easier to process and more susceptible to damage from chemical services than medium or coarse hair
Density
-Hair Density- measures the number of individual hair strands on one square inch of the scalp.
-Classified as Low-thin, Medium-medium, High-Thick
Porosity
Hair porosity- the ability of the hair to absorb moisture
-Healthy hair, resistant to being penetrated by moisture (Hydrophobic)
-Porous hair has a raised cuticle layer that easily absorbs moisture and is called (Hydrophilic)
Elasticity
-The ability of the hair to stretch and return to its original length without breaking
-Wet hair can stretch up to 50% of its original length and return to the same length without breakage
-Dry hair stretches about 20% of its length
-Hair with low elasticity is brittle and breaks easily
-Low elasticity require a milder solution with a lower PH
Hair stream
-Flowing in the same direction, resulting from the hair follicles sloping in the same direction
-Hair flowing in the opposite direction will result in the hair having a natural part on the head.
Whorl
-Hair leaves the follicle at an angle; the hair will lie in a particular direction forming patterns on the head
-Streams spiral outward, from a center point
-Usually going in a clockwise direction and sometimes more than one whorl can be seen on the head.
Cowlick
-Due to Particular pattern of hair stream on the forehead
-Front hairline; short, thick hair, but can be located on any part of the head.
