It's not just a phase, mom!
transition period between the growth and resting phases of a hair follicle
catagen phase
strong chemical side bond that joins the sulfur atoms of two neighboring cysteine amino acids
disulfide bond
has a bulb shape and contains living cells that will form the hair strand
hair bulb
hair that grows straight up or at a different angle than the other hair
cowlick
yellow to red pigment found in natural blonde to red shades of hair
final phase in the hair cycle that lasts until the fully grown hair is shed
telogen phase
bonds created when disulfide bonds are broken by hair relaxers
Lanthionine bonds
fibrous protein layer of the hair
cortex
short, fine, unpigmented hair that appears on the body
vellus hair
ability of the hair to absorb moisture
porosity
hair phase during which new hair is produced
anagen phase
chemical bond that joins amino acids to each other, end-to-end
peptide bond
glands connected to hair follicles that secrete sebum
Sebaceous glands
hair grows in a circular pattern on the crown of the head
whorl
brown and black pigment and is the predominant pigment in black and brunette hair
eumelanin
scientific study of hair and its diseases and care
trichology
weak physical cross-link side bond that is easily broken by water or heat
hydrogen bond
innermost layer found in coarse hair and beard hair
medulla
short, fine hair that covers a fetus and generally sheds within a few weeks of birth
lanugo hair
measures the number of individual hair strands on 1 square inch of scalp
density
cells in the hair bulb mature, fill with keratin, move upward, lose their nucleus, and die
keratinization
bonds that cross-link polypeptide chains for extreme strength and elasticity
side bonds
formed from cells that resemble shingles on a roof
cuticle
long, coarse, pigmented hair found on the scalp, legs, arms, and body
terminal hair
ability of the hair to stretch and return to its original length without breaking
elasticity