Hair Theory Flashcards
What are the 2 main purposes of hair?
Adornment and Protection from heat and cold and injury
What cells are the only ones alive in the hair
The cells in the hair bulb
Define “Primitive Hair Germ”
Forms in the basal layer. Works it way down into the lower layer of the skin for nourishment. Pulls upper layer down with it creating the root sheath.
Where does hair grow from?
The root sheath
Define “Basal Layer”
Inner most layer of the epidermis
Define “Sebaceous (oil) Glands”
Produces sebum to prevent hair skin from becoming too dry
Define “sebum (oil)”
Mixes with perspiration to form the acid mantle
Define “Arrector Pilli”
Goose bumps. Causes hair to stand up when scared or cold. It is a muscle
Define “Hair Follicle”
tube like structure (pore) that surrounds the root and strand of a hair
Define “Papilla”
Filled with capillaries that supply nourishment to cells around it
What is the correct formation of the hair bulb?
- Primitive Hair Germ
- Basal Layer
- Sebaceous Glands
- Hair Follicle
Define a “straight” hair bulb and its follicle shape
It’s perpendicular to scalp with a slight “tilt”
Follicle Shape” Round or Oval
Define a “Wavy” hair bulb and its follicle shape
Its more curved to scalp
Follicle Shape: More Oval
Define “Curly” hair bulb and its follicle shape”
Its almost parallel to the scalp
Follicle Shape: Flattened elliptical
What determines the shape of the hair shaft?
the Shape of the follicle determines the shape of the hair shaft as it grows from the follicle
What are the 2 primary parts of the hair shaft?
Hair Root
Hair Fiber
Define “Hair Root”
Portion of hair inside the hair follicle under the skins surface
Define “Hair Fiber”
Portion of hair that extends above the skins Surface
What undergoes cells division to produce cells that ultimately keratinize and form the three layers of hair?
Germinal Matrix
Name the three layers of the hair
Cuticle
Cortex
Medulla
Define “Cuticle”
Outer covering of the hair shaft.
Its hard and resistant
Define “Cortex”
Second Layer with a unique protein structure. Soft and Elastic
Define “Medulla”
Central core of the hair shaft
Define “Acid Mantle”
Protects cuticle of hair fibers. Maintains the natural Ph of hair skin. Friction
What is the “process of cells changing shape, drying out and forming keratin protein”?
Keratinization
What are the C.O.H.N.S Elements?
Carbon
Oxygen
Hydrogen
Nitrogen
Sulfer
What are the stages of hair growth?
- Anagen
- Catagen
- Telogen
Define “Anagen” in the growth stage of hair
its active growing and is attached to the root sheath. 90 % of hair in this stage color is darker
Define “Catagen” in the growth stage of hair
Transitional stage.
Cell division stops.
Usually lasts a couple weeks
Define “Telogen” in the growth stage of hair
Resting Stage.
Not attached to root sheath.
Hair fall out
What are three factors that can effect the behavior of hair?
Heredity
Environment or weather
Products or appliances
What is “Heredity”?
Determines structure, color, shape, and diameter
What behavior does the environment and weather do to the hair?
Affects the absorption of moisture from air
How does products and appliances affect the behavior of hair?
Affects structural organization of hair
Define “Melanin”
Amount, Size and Distribution
What contains the pigment of melanin?
Melanosomes which is produced by melanocytes
What influences the result of hair?
Melanin
What hair color will be produce with Eumelanin?
Brown/Black
What hair color will be produce with Pheomelanin?
Red/Yellow
What is Albinism?
The total lack of pigmentation in hair and skin
What produces the gray color in hair?
Reduced melanin in cortex. Referred to as mottled hair. Grows from papilla with gray color. Results usually with aging. Can be caused by serious illness, emotional conditions and heredity
Define “Density”
Number of active hair follicles per square inch on scalp. Usually referred to as light medium or heavy. Influences the amount of hair that should be parted and wrapped around a perm tool, roller, or curling iron.
Define “Texture”
Degree of coarseness or fineness in the hair fiber. Fine hair is more cuticle then coarse hair.
Define “Porosity”
Ability of the hair to absorb moisture, liquids, or chemicals
Define “Elasticity”
Ability of hair to stretch and return to its original shape without breaking. Normal hair is capable of stretching 1/5 20% of its length. Wet Hair is able to be stretched 40% to 50% of its length
Define “Lanugo”
Fine silky hair covering body before birth
Define “Vellus”
Short fine non-pigmented hair that replaces lanugo hair
Define “Terminal”
Long, thick pigmented hair such as scalp and eyebrow hair
Define “Androgenic hair loss”
Most common
Define “Alopecia”
Excessive hair loss, caused by fungal or bacterial infection or inflammatory disease of scalp. Occurs in both men and women.
Define “Androgenic Alopecia”
Progressive shrinking or miniaturization of certain scalp follicles. Most common form of alopecia. Male pattern baldness. thinning for females.
Define “Postpartum Alopecia”
Temporary Hair loss
Define “Alopecia Areata”
Autoimmune disease. Sudden loss of hair in round or irregular patches.
Define “Totalis”
Total loss of hair to scalp
Define “Universalis”
loss of hair over entire scalp and body
Define “Prematura”
Baldness early
Define “telogen effluvium”
premature shedding of hair during vesting stage
Define “Traction or traumatic alopecia”
Hair loss from excessive pulling
