Chp 11 Cosmetology Written Study Guide: Properties of Hair and Scalp

Vocabulary flashcards generated from the cosmetology lecture notes covering the structures, composition, growth phases, and disorders of human hair and scalp.

Hair follicle

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

Hair bulb

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

Dermapapillae

Small cone shaped elevations located at the base of the hair follicle that fit into the hair bulb, containing the blood and nerve supply that provides nutrients needed for growth.

Erector pili muscle

Minute involuntary muscle fibers in the skin inserted in the base of the hair follicle that contract due to fear or cold, causing goosebumps.

Sebaceous glands

The oil glands of the skin connected to the hair follicles that secrete an oily substance called sebum.

Sebum

An oily substance secreted by the sebaceous glands that lubricates the hair and skin.

Hair cuticle

The outermost layer of the hair consisting of a single overlapping layer of transparent, scale like cells that overlap like shingles on a roof.

Cortex

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

Medulla

The innermost layer of the hair composed of round cells, which is present in thick, coarse hair and beard hair, but may be absent in very fine, naturally blonde hair.

Conn's elements

The five major elements that make up human hair, skin, and nails: carbon, oxygen, hydrogen, nitrogen, and sulfur.

Keratinization

The process in which living cells originating in the hair follicle mature as they journey upward through the follicle.

Keratin

A fibrous protein that fills newly formed hair cells as they mature, move upward, lose their nucleus, and die.

Amino acids

Units that join together end to end like beads to form long protein chains.

Peptide bonds

Strong chemical bonds, also known as end bonds, that join amino acids together.

Polypeptide chain

A long chain of amino acids linked by peptide bonds.

Helix

The spiral shape of a coiled protein created when polypeptide chains intertwine with each other.

Hydrogen bond

A weak, physical, cross link side bond that is easily broken by water or heat, accounting for about one third of the hair's strength.

Salt bond

A weak, temporary cross link side bond broken by changes in pH, such as strong alkaline or acidic solutions, accounting for one third of the hair's overall strength.

Desulfide bonds

Strong chemical side bonds that join the sulfur atoms of two neighboring cysteine amino acids to create cysteine, accounting for about one third of the hair's overall strength.

Lanthanin bonds

Bonds created when hydroxide relaxers break and then convert disulfide bonds when the relaxer is rinsed from the hair.

Melanin

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

Eomelanin

A type of melanin pigment that provides dark brown and black color to hair.

Pheomelanin

A type of melanin pigment that provides natural hair colors from red and ginger to yellow blonde tones.

Wave pattern

Refers to the shape of the hair strand, described as straight, wavy, curly, or extremely curly.

Vela's hair

Short, fine, downy, unpigmented hair covering most of the body except the palms and soles of the feet, also known as lanugo.

Terminal hair

Long, thick, pigmented hair found on the scalp, legs, and arms that is coarser than Vela's hair and usually contains a medulla.

Anagen phase

The growing phase of the hair growth cycle.

Catagen phase

The transition phase of hair growth that lasts only $1$ to $2\text{ weeks}$, during which the follicle canal shrinks and detaches from the dermal papilla.

Telogen phase

The resting phase of hair growth that begins after catagen and lasts $3$ to $6\text{ months}$.

Canadies

The technical term for gray hair caused by loss of natural pigment in the hair.

Ringed hair

Hair characterized by alternating bands of gray and pigmented hair throughout the length of the hair strand.

Hypertrichosis

A condition characterized by the growth of terminal hair in areas of the body that normally grow vellus hair.

Tricapatillosis

The technical term for split hair ends, also known as split ends.

Tritorhexis nodosa

Knotted hair characterized by a dry, brittle condition with nodular swelling along the hair shaft where hair breaks very easily.

Monilextrics

A hair disorder where the hair tends to break between the beads or nodes.

Androgenic alopecia

A genetic hair loss condition affecting both men and women, characterized in men by male pattern baldness with a receding hairline and gradual disappearance of hair from the crown and frontal scalp.

Alopecia areata

An autoimmune disorder in which white blood cells stop hair growth during the anagen phase by mistakenly attacking affected hair follicles.

Postpartum alopecia

Temporary hair loss occurring at the conclusion of pregnancy, with growth usually returning to normal within $1\text{ year}$ after delivery.

Pitoriasis

The technical term for dandruff, characterized by excessive production and accumulation of skin cells.

Pityriasis capitis simplex

The term for classic dandruff.

Pityriasis tetodes

A more severe case of dandruff.

Tinea

The technical term for ringworm, characterized by itching, scales, and sometimes painful circular lesions.

Tinea capitis

Ringworm of the scalp, causing red papules or spots at the opening of hair follicles that cause hair to break.

Tinea favossa

A fungal infection characterized by dry, sulfur-yellow, cup-like crusts on the scalp called scutula.

Scutula

Dry, sulfur-yellow, cup-like crusts on the scalp characteristic of tinea favossa.

Piticulosis capitis

A contagious condition caused by head lice infesting the hair and scalp.

Furuncle

The technical term for a boil; an acute localized bacterial infection of the hair follicle that produces constant pain.

Carbuncle

An inflammation of the subcutaneous tissue caused by staphylococci.

Folliculitis

An infection of the hair follicle.

Coarse hair

Hair texture that has the largest diameter.

Medium hair

Hair texture that is the most common and considered normal.

Fine hair

Hair texture that has the smallest diameter and is more fragile.

Hair density

Measures the number of individual hair strands on $1\text{ square inch}$ of the scalp.

Hair porosity

The ability of the hair to absorb moisture, which is directly related to the condition of the cuticle layer.

Hair elasticity

The ability of hair to stretch and return to its original length; wet hair with normal elasticity will stretch up to $50\text{\%}$ of its original length and return without breaking.