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abnormal hair loss

alopecia areata

the sudden falling out of hair in round patches or baldness in spots; may occur on the scalp an elsewhere on the body

amino acids

the units of structure in protein


growth phase in the hair cycle in which new hair is synthesized

androgenic alopecia

male pattern baldness; hair loss charactersized by the miniaturization of terminal hair

arrector pili

minute, involuntary muscle fiber in the skin inserted in the base of the hair follicle


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


inflammation of the subcutaneous tissue caused by staphylococci; similar to a furuncle but more extensive


the breif transition period between the growth and resting phase of a hair follicle

COHNS elements

the five elements that make up human hair, (carbon, oxygen, hydrogen, nitrogen, and sulfur)


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


a tuft of hair that stands straight up


outermost layer of the hair, consisting of a single, overlapping layer of transparent , scale like cells

dermal papilla

small, cone shaped elevation located at the base of the hair folliclethat fits into the hair bulb

disulfide bond

chemical side bond that joins the sulfer atoms of two neighboring cysteine amion acids to create cystine


melanin that gives brown and black color to hair


tube like depression or pocket in the skin or scalp that contains the hair root

fragilitas crinium

technical term for brittle hair


boil; acute localized bacterial infection of the hair follocle

hair bulb

lowest area or part of a hair strand; the thickened, club shaped structure that forms the lower part of the hair root

hair density

the number of individual hair strands on one square inch of scalp

hair elasticity

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

hair porosity

the ability of the hair to absorb moisture

hair root

the part of the hair contained within the follicle, below the surface of the scalp

hair shaft

the portion of the hair that projects beyond the skin

hair stream

hair flowing in the same direction; the result of follocles sloping in the same direction

hair texture

the thickness or diameter of the individual hair strand

hydrogen bond

physical side bond that is easily by water or heat


condition of abnormal growth of hair; characterized by the growth of terminal hair in areas of the body that normally grow only vellus hair also called hirsuties


the process of being kertinazied; as newly formed cells in the hair mature, they fill up with kertain, move upward, lose their nucleus, and die; the hair shaft is a nonliving fiber composed of kertinized protein


innermost layer of the hair, sometimes referred to as the pith; composed of round cells; often absent in fine hair


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


technial term for beaded hair

pediculosis capitis

infestation of head lice

peptide bonds

chemical bond that joins amino acids to each other; also called end bond


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


dandruff; and inflammation of the skin characterized by the formation and flaking of fine, thin scales

pityriasis capitis simplex

technical term for scalp inflammation marked by dry dandruff, thin scales and an itchy scalp

pityriasis steatoids

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

polypeptide chain

long chain of amino acids linked by peptide bonds

postpartum alopecia

temporary hair loss experienced at the conclusion of a pregnancy

ringed hair

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

salt bond

physical side bond that is broken by changes in the pH


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

sebaceous glands

oil glands of the skin, connected to the hair follicles


fatty or oily secretion of the sebaceous glands which lubricates the hair and skin


resting phase; the final phase in the hair cycle that lasts until the fully grown hair is shed

terminal hair

the long, soft hair found on the scalp, also on legs, arms, adn body of both male and females


medical term for ringworm, contagious condition caused by vegetable parasites

tinea capitis

ringworm of the scalp

tinea favosa

ringworm caracterized by dry, sulfur yellow cup like crusts on the scalp, called scutula; also known as tinea favus or honeycomb ringworm


the science dealing with the hair , its diseases and care


technical term for split ends

trichorrhexis nodosa

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

vellus or lanugo

short downy hair that appears of the body, with the exception of the palms of the hands and the soles of the feet

wave pattern

amount of movement in the hair strand; described as straight, wavy curly and extremely curly


hair that forms a circular pattern as on the crown

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