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