Barbers need to know how products and _________ affect the structure of the hair.
chemicals
Barbers need to know how to keep a client’s hair and scalp in a healthy condition and how to differentiate between normal and ________ conditions.
abnormal
Barbers need to be able to perform a scalp and ________ analysis before performing a service.
hair
trichology
The scientific study of hair, its disorders, and its care is called trichology, which comes from the Greek words trichos (“hair”) and ology (“study of”).
The main structures of the hair root are
the follicle, bulb, dermal papilla, sebaceous glands, and arrector pili muscle.
Follicle
The hair follicle is the tubelike depression or pocket in the skin or scalp that contains the hair root.
Hair Bulb
The hair bulb is club-shaped structure that forms the lower part of the hair root and is the lowest part of the hair strand.
Dermal Papilla
The dermal papilla is a small, cone-shaped elevation at the base of the hair follicle that fits into the hair bulb.
Sebaceous Glands
The sebaceous glands consist of small, saclike structures with ducts that are attached to each hair follicle. They secrete an oily substance called sebum that lubricates the skin.
Arrector Pili
The arrector pili is a minute, involuntary muscle fiber in the skin attached to the base of the hair follicle.
The three main layers of the hair shaft are
the cuticle, cortex, and medulla
Cuticle
The hair cuticle is the outermost layer of the hair. It consists of a single overlapping layer of transparent, scale-like cells that look like shingles on a roof.
Cortex
The cortex is the middle layer of the hair. It is a fibrous protein core formed by elongated cells that contain melanin pigment
Medulla
The medulla is the innermost layer of the hair and is composed of round cells.
The essential elements in the human hair are
carbon, oxygen, hydrogen, nitrogen, and sulfur, often referred to as the COHNS elements.
Side bonds are of three types, consisting of hydrogen, salt, and disulfide bonds, which account for the strength and elasticity of _______ hair.
human
Hydrogen Bond
A hydrogen bond is a weak, physical, cross-link side bond that is easily broken by water or heat.
Salt Bond
A salt bond is a weak, physical side bond, which cross-links the polypeptide chains, but it reacts to changes in pH
Disulfide Bond
A disulfide bond, also known as a sulfur bond, is a strong covalent bond that is different from the physical side bond of hydrogen or salt bonds.
Natural hair color is the result of the ______ pigment found within the cortex.
melanin
Melanin are the tiny grains of pigment in the ________ that give natural color to the hair.
cortex
Eumelanin
Eumelanin provides brown and black color to hair.
Pheomelanin
Pheomelanin provides natural hair colors that range from red and ginger to yellow and light blond tones.
The wave pattern of hair refers to the shape of the hair strand and is described as straight, wavy, curly, and _________ curly.
extremely
The hair normally grows in _______ and sheds.
phases
The two main types of hair are vellus hair and _______ hair.
terminal
Vellus Hair
Vellus hair, or lanugo hair, is the short, fine, un-pigmented, downy hair.
Terminal Hair
Terminal hair is the long, coarse, hair found on the scalp, legs, arms, and bodies of males and females.
In normal, healthy hair, hair growth occurs in cycles. Each complete cycle has _______ phases that are repeated over and over throughout life.
three
Anagen: The Growth Phase
During the anagen phase, or growth phase, new hair is produced. New cells are manufactured in the hair follicle.
Catagen: The Transition Phase
The catagen phase is a transition period between the growth and resting phases of a hair strand.
Telogen: The Resting Phase
The telogenphase, or resting phase, is the final phase of the hair cycle.
It is normal to lose an average of ____ to 100 hairs per day.
75
Growth patterns that result in creating hair streams, whorls, and cowlicks are determined by the angle at which the hair emerges from the hair ________.
follicle
Hair Stream
A hair stream is hair that flows in the same direction. It is the result of follicles being arranged and sloping in a uniform manner.
Whorl
A whorl is hair that grows in a circular or swirl pattern. Whorls are most often seen at the crown.
Cowlick
A cowlick is a tuft of hair that stands straight up.
A hair that is shed in the telogen phase is replaced by a new hair, in that same follicle, in the next _______ phase.
anagen
Abnormal hair loss is called __________, which may appear in different forms as a result of a variety of abnormal conditions.
alopecia
The only FDA-approved hair loss treatments, which have been proven to stimulate hair growth, are _________ and finasteride.
minoxidil
Minoxidil
Minoxidil is a topical treatment that has been proven to stimulate hair growth.
Finasteride
Finasteride is an oral prescription medication for men only sold under the brand name Propecia, and is for use only in men.
Surgery
A hair transplant is the most common permanent hair replacement technique.
Hair disorders are ___________ conditions that include disorders such as canities, hypertrichosis, trichoptilosis, trichorrhexis nodosa, monilethrix, and fragilitas crinium.
noncontagious
Canities
Canitiesis the technical term for gray hair
Hypertrichosis
Hypertrichosis, also known as hirsuties, is a condition characterized by the growth of terminal hair on areas of the body that are normally covered with only vellus hair.
Trichoptilosis
Trichoptilosis is the technical term for splitends.
Trichorrhexis nodosa
Trichorrhexis nodosais the technical term for knotted hair.
Monilethrix
Monilethrixis the technical term for beaded hair.
Fraglitas Crinium
Fraglitas crinium is the technical term for brittle hair.
Pityriasis is the technical term for ________, which is characterized by the excessive production and accumulation of skin cells.
dandruff
Pityriasis Capitis Simplex
Pityriasis capitis simplex is the technical term for classic dandruff, characterized by scalp irritation, large flakes, and an itchy scalp
Pityriasis Steatoides
Pityriasis steatoidesis a more severe form of dandruff that is characterized by an accumulation of greasy or waxy scales mixed with sebum
Tinea is the medical term for ringworm. Ringworm is caused by_______organisms and is characterized by itching, scales, and, sometimes, painful circular lesions.
fungal
Tinea Capitis
Tinea capitisis commonly known as ringworm of the scalp
Tinea Barbae
Tinea barbae is a superficial fungal infection caused by dermatophytes occurring chiefly over the bearded area of the face.
Tinea Favosa
Tinea favosais also known as tinea favus or honeycomb ringworm.
The two most common parasitic infestations barbers may see in the barbershop are pediculosis capitis and ________.
scabies
Pediculosis Capitis
Pediculosis capitis is the infestation of the hair and scalp with head lice.
Scabies
Scabies is a highly contagious skin disease caused by mites that burrow under the skin.
Barbers may encounter bacterial staphylococci _________ in the barbershop in the form of different types of folliculitis.
infections
Folliculitis Barbae
Folliculitis barbae, or barber’s itch, is an infection of the hair follicles characterized by inflamed pustules in the bearded areas of the face and neck that may have hairs growing through the pustule.
Pseudofolliculitis Barbae
Pseudofolliculitis barbae, also referred to as razor bumps, is a chronic inflammatory condition that resembles folliculitis in terms of papules and pustules but is generally accepted to be caused by ingrown hair.
Sycosis Vulgaris
Sycosis vulgaris, also known as sycosis barbae, is a chronic bacterial infection involving the areas surrounding the follicles of the beard and mustache areas.
Furuncle
A furuncle, or boil, is an acute bacterial infection of a hair follicle, producing constant pain.
Carbuncle
A carbuncle is the result of an acute, deep-seated bacterial infection in the subcutaneous tissue.
In addition to wave and growth patterns, barbers should be able to analyze the hair’s texture, density, porosity, and ________.
elasticity
When analyzing the _____, comb through the hair gently while parting it to check for hypertrophies, abrasions, and parasites; do not scrape the scalp.
scalp
Hair texture refers to the degree of _________ or fineness of individual hair strands, which may vary on different parts of the head.
coarseness
Hair density
Hair density refers to the number of individual hair strands per square inch of scalp area and is classified as thick, average, or thin, or as high, medium, or low density.
Hair porosity
Hair porosity is the ability of the hair to absorb moisture.
Hair elasticity
is the ability of the hair to stretch and return to its original length without breaking and is an indication of the strength of the side bonds in the hair.
Hair is chiefly composed of a fibrous protein called
keratin
That portion of the hair found beneath the skin surface is called the hair
root
A tubelike depression in the skin or scalp that encases the hair root is the hair
follicle
A small, cone-shaped elevation at the base of the hair follicle is called the
dermal papilla
Sac-like structures with ducts that are attached to each hair follicle are called
sebaceous glands
An involuntary muscle fiber attached to the underside and base of the hair follicle is the
arrector pili muscle
The three main layers of the hair shaft are
cuticle, cortex, and medulla
To penetrate the cuticle layer in order to reach the cortex, a solution must be
more alkaline than the hair
Hair cells mature in the follicle through a process known as
keratinization
The elements found in human hair are carbon, oxygen, hydrogen, nitrogen, and
sulfur
A strong chemical bond in the hair is the
peptide bond
Once disulfide bonds are broken, they can
never be re-formed
A solution that will not re-form disulfide bonds is
hydroxide relaxers
The type of melanin that provides brown and black color to hair is
eumelanin
The shape of the hair strand is referred to as the
wave pattern
Hair that flows in the same direction is known as a
hair stream
New hair is produced during the _________ phase.
anagen
On average, the entire growth process of hair repeats itself once every
four or five years
The texture of hair that has the largest diameter is _________ hair.
coarse
Alopecia is the technical term for any abnormal type of
hair loss
Small, white scales appearing on the scalp and hair is a sign of
pityriasis
Tinea capitis’ red papules can be found at the opening of the
hair follicles
Clients with tinea, pediculosis, or a scabies condition should be
referred to a physician
The common term for a furuncle is
boil
__________ is measured by the diameter of a hair strand.
Texture