Chapter 11 hair and scalp
How many pounds of dead skin does the average person shed a year
9lbs
Hypertrichosis
A condition of abnormal growth of hair
Polypeptide chain
A long chain of amino acids linked by peptide bonds
Hydrophilic
A term that means easily absorbs moisture
Hydrophobic
A term that means resistant to being penetrated by moisture
Alopecia
Abnormal hair loss
Furuncle
An acute, localized bacterial infection of the hair follicle
Alopecia areata
An autoimmune disorder that causes the affected hair follicles to be mistakenly attacked by a persons own immune system
Carbuncle
An inflammation of the subcutaneous tissues caused by staphylococci
1/2 inch
Average growth of healthy scalp hair per month
35-40 hairs per day
Average rate of hair loss per day
Main elements that make up human hair and their percentage in normal hair
Carbon 51% Oxygen 21% Hydrogen 6% Nitrogen 17% Sulfur 5%
Scabies
Causes by a parasite called a mite
Ringed hair
Characterized by alternating bands of gray and pigmented hair
Extremely curly hair
Cross sections appear flattened and vary in shape and thickness along their length Shape of cross-section of hair always relates to the amount of curl in the hair Often has low elasticity
Tinea favosa
Dry, sulfur-yellow, cuplike crusts on the scalp called scutula
Cowlick
Due to a particular pattern on hair stream on the forehead
COHNS
Five elements that makeup human hair are referred to as _________ , also found in the skin and nails
Tinea capitis
Fungal infection characterized by red papules, or spots, at the opening of the hair follicles
Hair stream
Hair flowing in the same direction
Protein
Hair is composed of ___________ that grows from cells originating within the hair follicle
Middle layer
Hair of the cortex Percentage of the total weight of hair that comes from cortex: 90%
Whorl
Hair stream that spirals outward from a central point
Scutula
Has distinctive odor
Hydrogen bond
Is a weak, physical, cross-link side bond that is easily broken by water or heat; these bonds reform when the hair dies
Porosity
Is the ability of the hair to absorb moisture
Elasticity
Is the ability of the hair to stretch and return to its original length without breaking
Medulla
Is the innermost layer of the hair shaft and is composed of round cells
Androgenic alopecia
Is the result of genetics, age, or hormonal changes that cause terminal hair to miniaturize In men known as male pattern baldness
Tinea looks like
Itching, scales, and sometimes painful circular lesions
Pheomelanin (melanin)
Lighter pigment that provides natural colors ranging from red and ginger to yellow and blonde tones
Hair root and hair shaft
Located below the surface of the epidermis, and the portion of the hair that projects above the epidermis
Terminal hair
Long , course, pigmented hair found on scalp, legs, arms, and bodies of males and females
Bulb
Lowest part of the hair strand
Density
Measures the number of individual hair stands on one square inch of scalp Low, medium, high
Eumelanin (melanin)
Natural dark brown to black color
Genetics
Natural wave patterns are the result of _____________
Wave pattern
Of hair refers to the shape of the hair strand and is described as straight , wavy, curly , or extremely curly
Sebaceous glands
Oil glands in the skin that are connected to the hair follicles
Hair cuticle
Outermost layer of the hair Layer description: provides a barrier that protects the inner structure of the hair as it lies tightly against the cortex Healthy cuticle: Prevents damage to hair fiber
Two principle types of dandruff and their characterizations
Pityriasis capitis simplex-scalp irritation, large flakes, itchy scalp Pityriasis steatoides-more severe case, accumulation of greasy or waxy scales, mixed with sebum, that stick to the scalp in crusts
Malassezia
Research confirms that dandruff is the result of a fungus called __________________, a naturally occurring fungus that is present on all human skin
Between ages 15 and 30
Scalp hair tend to grow most rapidly
Trichology
Scientific study of hair and its diseases and care, which comes from the greek words trichos, meaning "hair" , and ology, meaning "the study of"
Vellus hair
Short , fine , unpigmented and downy hair that appears on the body Men retain less of this hair than women
Dermal papilla
Small, cone-shaped elevation located at the base of the hair follicle that fits into the hair bulb (contains the blood and nerve supply that provides the nutrients needed for hair growth)
Arrector pili muscle
Small, involuntary muscle in the base of the hair follicle
Helix
Spiral shape of a coiled protein
Disulfide bond
Strong, chemical side bond that joins the sulfur atoms of two neighboring cysteine amino acids to create one cystine
Monilethrix
Technical term for beaded hair
Fragilitas crinium
Technical term for brittle hair
Canities
Technical term for gray hair
Trichorrhexis nodosa
Technical term for knotted hair
Tinea
Technical term for ringworm
Trichoptilosis
Technical term for split ends
Anagen
The Growth phase of new hair
Pediculosis capitis
The infestation of the hair and scalp with head lice
Keratization
The maturation of these cells is a process called __________
Minoxidil and finasteride
The only two products that have been proven to stimulate hair growth and are approved by the food and drug administration(FDA) for sale in the US
Telogen
The resting phase
Peptide bond
The strong, chemical bond that joins amino acids
Catagen
The transition period between the growth and resting phases
Hair bulb
Thickened, club-shaped structure that forms the lower part of the root
Texture
Thickness or diameter of the individual hair strand Course, medium, fine
Oxidation hair coloring , wet setting, thermal styling
Three different hair properties for which the cortex is responsible
Hair cuticle, cortex, medulla
Three main layers of the hair shaft
Melanin
Tiny grains of pigment in the cortex that give natural color to the hair
Hair follicle
Tube-like depression or pocket in the skin or scalp that contains the hair root
Vellus hair and terminal hair
Two main types of hair found on the body
Congenital and acquired
Two types of canities
Amino acids
Units that are joined together and makeup proteins
Salt bonds
Weak, physical, cross-linked side bonds between adjacent polypeptide chains
Alopecia totalis
When alopecia areata progresses to total scalp hair loss , when it results in complete body hair loss, it is called alopecia universalis
Seborrheic dermatitis
When pityriasis steatoides is accompanied by redness and inflammation
Sebum
sebaceous glands secrete a fatty or an oily substance called _____________, which lubricates the skin