Chemical composition of hair
the three types of side bonds
What are hydrogen, salt and disulfide
the study of hair, including it diseases and care
What is trichology
responsible for the hair's strength, elasticity and color
What is the cortex
Natural hair color is the result of a pigment called
What is melanin
hair's ability to stretch and return to its original length without breaking
What is elasticity
a service that will alter disulfide bonds
What is relaxers
the hair, skin and nails are part of the ___________ system
What is integumentary
also known as the hair's pith or core and is sometimes absent from the hair
What is the medulla
What is pheomelanin
diameter of an individual hair strand
What is texture
broken by water or heat
What is hydrogen bond
located below the epidermis
the hair root
outermost layer of the hair and softens and swells during chemical services
What is the cuticle
brown to black pigment
What is eumelanin
hair with ___ _______ has a very healthy cuticle where the scales lie flat
What is low porosity
The side bonds that link across the polypeptide chains in the cortex are responsible for hair's strength and ____________.
What is elasticity
involuntary muscle in the dermis that attaches to the hair. (responsible for goosebumps)
What is the arrector pili
contributes to about 90% of hair's strength
What is the cortex
technical term for gray hair
What is canities
the number of individual hair strands in 1 sq. inch
What is density
broken by a change in pH
What is a salt bond
contains living cells that form the hair strand
What is the hair bulb
consists of the cuticle, cortex and medulla
What is the hair shaft
gray hair that occurs as we age
What is acquired canities
overactive sebaceous glands cause ___ ___ __ ____ while underactive sebaceous glands cause ___ ___ ___ ____
What is oily hair and scalp
What is dry hair and scalp