Structures of the hair
The _____ is the lowest part of a hair strand.
The Hair Bulb
Hair is approximately _____ % protein.
90 %
The growth phase during which new hair is produced is called?
Anagen Phase
The _____ is the outermost layer of hair.
Cuticle
A _____ bond is a physical bond easily broken by water or heat.
Hydrogen
The oily substance secreted from the sebaceous gland is called:
Sebum
What are the major elements that make up human hair?
COHNS elements
The _____ phase signals the end of the growth phase.
Catagen Phase
The middle layer of the hair strand is?
Cortex
Name the three types of side bonds.
Hydrogen Bond
Salt Bond
Disulfide Bond
What is the tiny involuntary muscle in the base of the hair follicle?
The arrector pili
The process whereby living cells mature and begin their journey up the hair shaft is called?
Keratinization
what percent of the hair is in the Telogen Phase at one time?
10%
The medulla is composed of _____ cells.
Round cells
A peptide bond links a long chain of amino acids is called a ________?
A polypeptide chain
What is the tube-like depression in the skin or scalp that contains the hair root is:
The Follicle
For chemicals to penetrate a healthy cuticle hair layer they must have what?
An alkaline pH
The long coarse pigmented hair found on the scalp, legs, arms, and bodies of males and females is called?
Terminal Hair
wet hair with normal elasticity will stretch up to ____ % of its original length.
50%
Hydrogen is a side bond broken by water or heat.
How is a Hydrogen bond re-formed?
By drying or cooling
Two parts of a mature hair strand of human hair are:
Hair Root & Hair Shaft
Name the five elements found in skin, hair, and nails.
Carbon
Oxygen
Hydrogen
Nitrogen
Sulfur
Vellus hair is known as?
Lanugo Hair
(luh-noo-gow - hehr)
The average growth of healthy scalp hair is ______ per month.
1/2" or (1.25 cm)
The chemical bonds that hold together the amino acid molecules are called?
Peptide bonds