The study of hair is known as_________________.
trichology
What small involuntary muscle is attached to the underside of a hair follicle?
arrector pili
Of the 20 amino acids that make up hair, a person must obtain _____________of the essential amino acids from daily diet.
nine
The chemical bond that joins amino acids to each other is called a____________.
peptide bond
The cortex contains coloring matter in the form of minute grains of________ , or pigment.
melanin
Oil glands of the skin, connected to the hair follicles, are known as_______________.
sebaceous glands
What structure is described as a small, cone-shaped elevation located at the bottom of the hair follicle?
dermal papilla
Normal hair contains ______________percent of the element carbon.
51
In the cortex, a side bond that is easily broken by strong alkaline or acidic solutions is a called a bond.
salt
Pheomelanin provides natural hair colors from ________________to yellow and blond tones.
red and ginger
Long, coarse, pigmented hair found on the scalp, legs, arms, and body is known as__________.
terminal hair
What is the lowest part of the hair strand?
hair bulb
Normal hair contains _______________percent of the element oxygen.
21
What term refers to an infection of the hair follicles frequently caused by staphylococcus or other bacteria?
folliculitis
The three main layers of the hair shaft are the______________________.
cuticle, cortex, and medulla
Canities is the technical term for__________ .
gray hair
What structure in the skin or scalp encases a hair root?
Hair follicle
In the makeup of normal human hair, what COHNS element is present in the lowest percentage?
Sulfur
What contagious condition is caused by head lice?
pediculosis capitis
What substance in the cortex gives natural color to the hair?
Melanin
When a client exhibits signs of __________, salon service should be limited to referring the client to a physician for medical treatment.
scabies
A mature strand of human hair is divided into two principal parts known as the_______________.
hair root and hair shaft
As newly formed cells mature, they fill up with a fibrous, then move upward, lose their nucleus, and die. This process is called keratinization.
protein
The technical term for hair that is in a dry, brittle condition with nodular swellings along the hair shaft is?
trichorrhexis nodosa
All hair follicles have the same structure and cycle through the same three phases, which are_____________.
anagen (growing), catagen (transitional), and telogen (resting)