CHAPTER 9 PROPERTIES OF HAIR.txt

Alopecia

Abnormal hair loss.

Alopecia Areata

The sudden falling out of hair in round patches or baldness in spots; may occur on the scalp and elswhere on the body.

Amino acids

units that are joined togehter end to end by peptide bonds to form the polypeptide chains that comprise porteins.

Anagen

growth phase in the cycle in which a new hair shaft is created

androgenic alopecia

hair loss characterized by miniaturization of terminal hair which is converted to vellus hair; in men it is known as male pattern bladness.

arrector pili

minute, involutary muscle in the base of the hair follice that causes "goose bumps

canities

Technical term for gray hair; results from the loss of the hair's natural melanin pigment

Carbuncle

inflammation of the subcutaneous tissue caused by staphylocci; similar to furuncle but larger.

Catagen

the brief transistion period between the growth and resting phases of a hair follicle

COHNS element

the five elements that make up human hair, skin , tissue and nails ( carbon, oxygen, hyrogen, nitrogen, and sulfur)

Cortex

middle layer of the hair; a fibrous protein core formed by elongated cells contaiong melanin pigment.

cowlick

tuft of hair that stands straight up.

cuticle

outermost layer of hair consisting of a single overlappoing layer of transparent, scale-like cless.

dermal papilla

small cone-shaped elevation located at the bace of the hair follicle that fits into the hair bulb

disulifide bond

Strong chemical side bonds that join the sulfur atoms of two neighboring cysteine amino acids to create cysine, which joins together two polypeptide strands like rungs on a ladder

eumelanin

melanin that gives brown and black color to hair.

follicle

Tube-like depression or pocket in the skin or sclap that contains the hair root

Fragilitas Crinium

technical term for brittle hair.

Fruncle

boil; acute. localized bacterial infection of the hair follicle.

hair bulb

lowest part of a hair strand; the thickened, club-shaped structure that form the lower part of the hair root.

hair density

the number of indiviual hair strands found on 1 square inch of scalp

hair elasticity

ability of the hair to stretch and return to its original length without breaking.

Hair porosity

ability of the hair to absorb moisture

hair root

the part of the hair contained within the follicle, below the surfaces of the scalp.

hair shaft

the portion of hair that projects beyond the skin.

hair stream

hair flowing in the same direction, resulting from follicles slpoing in the same direction.

hair texture

thickness or diameter of the indiviual hair strands

helix

spiral shape created by polypeptide chains that intetwine around each other

hyrogen bond

weak physical side bond that is easily broken by wather or heat.

hypertrichosis (hirsuties)

condition of abnormal growth of hair, charaterized by the growth of terminal hair in areas of the body that normally grow only vellus hair.

integument

largest and fastest growing organ of the body; composed of the hair skin and nails.

keratinization

process by which newly formed cells in the hairr bulb mature, fill with keratin, move upward, lose their nucleus, and die.

malassezia

naturally occuring fungus that is present on all human skin, and is responsible for dandruff.

medulla

innermost lyer of the hair, composed of round cells, often abesnt in fine hair.

melanin

tiny grains of pigment in the cortex that give natural color to the hair

monilethrix

technical term for beaded hair

pediculosis capitits

infestation of the hair and scalp with head lice.

peptide bond or end bond

chemical that joins amino acids to each other, end to end, to form polypeptide chain.

pheomelanin

melanin that provides natural hair colors from red and ginger to yellow/blond tones.

pityriasis

dandruff; and infalmmation of the skin characterzied by formation and flakin of fine, thin scales.

pityriasis capitits simplex

technical term for classic dandruff; characterized by scalp irritaion . large flakes. and itchy scalp.

pityriasis steatoides

scalp inflammation marked by fatty(greasy or waxy) types of dandruff.

polypeptide chain

long china of amino acids linked by peptide bonds

pospartum alopecia

temporary hair loss experiences at the conclusion of pregnancy

ringed hair

variety of canites characterized by alternating bands of gray and pigmented hair throughout the length of the hair strand

salt bond

a weak, temporary side bond between adjacent polypeptide chains.

scabies

hichly contagious disease caused by mites that burrow under the skin.

scutula

dry, sulfur-yellow, cup-like crusts on the scalp in tinea favosa or favus.

sebaceous flands

oil glands of the skin connected to hair follicles.

seborrheic dermatitis

medical term for pityriasis steatioides accompanied by redness and inflammation.

sebum

oily secretion ofthe sevaceous flands, which lubricates the hair and skin

telogen

resting phase; the final phase in the hair cycle that lasts until the fully grown hair is shed. About 10% of sclap hair is in the telogen phase at any one time

Terminal hair

long hair found on the scalp, as well as on legs, arm, and body of both males and females

tinea

medical term for ringworm a contagious conditon caused by fungal infection

tinea capitis

fungal infection characterized by red papules, or spots at the opening of hair follicles

tinea favosa ( tinea favus)

fungal infection caraterized by ry , sulfur-yellow, cup-like crusts on the scalp, called scutula.

trichology

science dealing with the study of hair its diseses and care.

trichoptilosis

technical term for split ends.

trichorrhexis nodosa

knotted hair characterized by brittleness and the formation of nodular swellings along tha hair shaft.

vellus or lanugo

short, fine, unpigmented downing hair that appears on the body, with the exception of the palms of the hands and the soles of the feet

wave patterm

amount of "movement" in the hair strand; described as straight, wavy, curly, and extermely curly.

whorl

hair that forms in a circular pattern, as on the crown.