Trichology

What term refers to the scientific study of hair and its diseases and care?

trichology

The Greek word trichos means ___.

hair

The hair, skin, nails, and glands are part of the ___ system.

integumentary

What part of the hair is located below the surface of the epidermis?

hair root

The pocket or tube-like depression in the scalp or skin that contains the hair root is the hair ___.

follicle

The thickened, club-like structure that forms the lower part of the hair root is the ___.

hair bulb

The small, involuntary muscle fiber in the base of the hair follicle is the ___.

arrector pili

The substance secreted by the sebaceous glands is called ___.

sebum

What is the oily substance secreted by the skin’s oil glands that lubricates the hair and skin?

sebum

What is the outermost layer of hair?

hair cuticle

What layer of the hair shaft creates the shine and the smooth, silky feel of healthy hair?

hair cuticle

A lengthwise section of hair shows that cuticle scales overlap and each individual cuticle scale is attached to the ___.

cortex

The fibrous protein core formed by elongated cells that contains melanin pigment is the ___.

cortexH

Hair is composed of protein that grows from cells originating within the ___.

hair follicle

The hair shaft that emerges from the scalp is a nonliving fiber composed of ___.

keratinized protein

Hair is approximately ___ percent protein.

90

The major elements that make up human hair are carbon, oxygen, hydrogen, nitrogen, and sulfur, often referred to as ___.

COHNS elements

The units of structure that build protein and are joined together end to end like pop beads are ___.

amino acids

A long chain of amino acids linked by peptide bonds is called a ___ chain.

polypeptide

The three different types of side bonds that link chains of amino acids together are ___.

hydrogen, salt, and disulfide

A physical side bond that is easily broken by water and heat is a ___ bond.

hydrogen

What type of bond is broken by wetting the hair with water and is reformed when the hair dries?

hydrogen bond

A weak, physical, cross-link side bond between adjacent polypeptide chains that is broken by changes in pH is a ___ bond.

salt

Hydroxide chemical relaxers break disulfide bonds and convert them to ___ bonds.

lanthionine

All natural hair color is the result of pigment called ___.

melanin

The pigment that provides brown or black color to hair is ___.

eumelanin

What term refers to the shape of the hair strand?

wave pattern

What is the cross-section shape of curly hair?

oval

Vellus hair is also known as ___ hair.

lanugo

What type of hair is short, fine, unpigmented, and downy?

vellus hair

What is the growth phase during which new hair is produced?

anagen

What is the resting phase or final phase of the hair cycle that lasts until the fully grown hair is shed?

telogen phase

The sudden falling out of hair in round patches or baldness in spots is known as___.

alopecia areata

Temporary hair loss experienced at the end of a pregnancy is called ___.

postpartum alopecia

What is the technical term for gray hair?

canities

The condition of abnormal hair growth of terminal hair is referred to as ___.

hypertrichosis

Trichoptilosis is the technical term for ___.

split ends

What is a condition that is characterized by brittleness and the formation of nodular swellings along the hair shaft?

trichorrhexis nodosa

What is the technical term for beaded hair?

monilethrix

What is the medical term used to describe dandruff?

pityriasis

Current research confirms that dandruff is the result of a fungus called ___.

malassezia

What is a severe type of dandruff characterized by an accumulation of greasy or waxy scalp scales mixed with sebum?

pityriasis steatoides

What is a scalp disorder characterized by dry, sulfur-yellow, cup-like crusts on the scalp?

tinea favosa

What is a highly contagious skin disease caused by a parasite called a mite?

scabies

The thickness or diameter of the individual hair strand is referred to as hair ___.

texture

What type of hair has the largest diameter and usually requires more processing?

coarse hair

The ability of the hair to absorb moisture is hair ___.

porosity

Chemical services performed on hair with low porosity require a ___ solution.

more alkaline

Hair flowing in the same direction, as the result of follicles sloping in the same direction, is known as a ___.

hair stream

Dry hair and scalp should be treated with products that contain moisturizers and ___.

emollients