Chapter 9 - Hair Anatomy Flashcards
Hair porosity
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 hair that projects beyond the skin
Hair stream
Hair flowing in the same direction, resulting from follicles sloping in the same direction
Hair texture
Thickness and diameter of the individual hair strands
Helix
Spiral shape created by polypeptide chains that intertwine around each other
Hydrogen bond
Weak physical side bond that is easily broken by water or heat
Hypertrichosis
Condition of abnormal growth of hair , characterized by the growth of the growth of the growth of terminal hair in areas of the body that normally grow only vellum hair
Malassezia
Naturally occurring fungi that is present on all human skin, and is responsible for dandruff
Medulla
Innermost layer of the hair, composed of round cells; often absent in fine hair
Melanin
Tiny grains of pigment on the cortex that give natural color to the hair.
Monilethrix
Technical term for beaded hair
Pediculosis capitis
Infestation of the hair and scalp with head lice
Peptide bond or end bond
Chemical bond that joins amino acids to each other, end to end, to form a polypeptide chain
Pheomelanin
Melanin that provides natural hair colors from red to ginger to yellow/blond tones
Pityriasis
Dandruff; an inflammation of the skin characterized by the formation and flaking of fine, then scales.
Pityriasis capitis simplex
Technical term for classic dandruff; characterized by scalp irritation, large flakes, and itchy scalp
Pityriasis steatoides
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 o the hair strand
Salt bond
A weak, temporary side bond between adjacent polypeptide chains. Broken down by salt and ph levels
Scabies
Highly contagious disease caused by mites that burrow under the skin
Scutula
Dry, sulfer-yellow, cup-like crusts on the scalp in tinea favosa or favus
Sebaceous glands
Oil glands of the skin connected to the hair follicle
Seborrheic dermatitis
Medical term for pityriasis steatoides accompanied by redness and inflammation
Sebum
Oily secretion of the sebaceous glands, 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
Terminal hair
Long hair found on the scalp characterized by red papules, or spots at the opening of hair follicles
Tinea
Medical term for ringworm, a contagious condition caused by fungal infections
Tinea favosa ( tinea favus )
Fungal infection characterized by dry, sulfur-yellow, cup-like crusts on the scalp, called scuttle
Trichology
Science dealing with the study of hair, it’s diseases, and care
Trichoptilosis
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, fine, unpigmented downy hair that appears on 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, an extremely curly
Whorl
Hair that forms in a circular pattern, as on the crown
Hair elasticity
Ability of the hair to stretch and return to its original length without breaking
Integument
Largest and fastest growing organ of the body; composed of the hair, skin, an nails
Keratinization
Process by which newly formed cells in the hair bulb mature, fill with keratin, move upward, lose the nucleus, an die
Hair bulb
Lowest part of a hair stand; the thickened, club-shaped structure that forms the lower part of the hair root
Hair density
The number of individual hair strands found in 1 square inch of the scalp
Eumelanin
Melanin that gives brown and black color to hair
Follicle
Tube-like depression or pocket in the skin or scalp that contains the hair root
Furuncle
Boil; acute, localized bacterial infection of the hair follicle
Fragilitas crinium
Technical term for brittle hair
Disulfide bond
Strong chemical side bonds that join the sulfer atoms of two neighboring cysteine amino acids to create cysteine, which join together two polypeptide strands like rungs on a ladder
Cowlick
Tuft of hair that strands straight up
Cortex
Middle layer of the hair; a fiberous protein core formed by elongated cells containing melanin pigment
Cuticle
Outermost late of hair; consisting of a single, overlapping layer of transparent, scale-like cells
Dermal pappilla
Small, cone-shaped elevation located at the base of the hair follicle that fits into the hair bulb
Arretor pili
Minute, involuntary muscle in the base of the hair follicle that causes “goose bumps”
Canities
Technical term for gray hair, results from the loss of the hairs natural melanin pigment
Catagen
The brief transition period between the growth and resting phases of a hair follicle
Carbuncle
Inflammation of the subcutaneous tissue caused by staphylococci; similar to a furuncle but larger
COHNS Elements
Five elements that make-up human hair, skin, tissue, and nails. (Carbon, oxygen, hydrogen, nitrogen, and sulfur)
Anagen
Growth phase in the hair cycle in which a new hair shaft is created
Alopecia areata
Sudden falling out of hair in round patches or baldness in spots, may occur on the scalp and elsewhere on the body
Androgenic alopecia
Hair loss characterized by miniaturization of terminal hair which is converted to vellus hair; in men, it is known as male pattern baldness
Alopecia
Abnormal hair loss
Amino acids
Units that are joined together end to end by peptide bonds to form the polypeptide chains that comprise proteins
