3 parts of The Hair Shaft
Nitrogen
17%
lanthionine bonds
The bonds created when disulfide bonds are broken by hydroxide chemical hair relaxers after the relaxer is rinsed from the hair.
Middle layer of the hair; a fibrous protein core formed by elongated cells containing melanin pigment.
what is the cortex
Hydrogen
6%
Salt bonds
A weak, physical, cross-link side bond between adjacent polypeptide chains.
Also known as resting phase; the final phase in the hair cycle that lasts until the fully grown hair is shed.
telogen phase
Outermost layer of hair; consisting of a single, overlapping layer of transparent, scale-like cells that look like shingles on a roof.
what is the hair cuticle
21%
Oxygen
Side bonds
Bonds that cross-link the polypeptide chains together and are responsible for the extreme strength and elasticity of human hair.
Pheomelanin
The lighter pigment that provides natural colors ranging from red and ginger to yellow and blond tones.
Also known as growth phase; phase during which new hair is produced.
anagen phase
Innermost layer of the hair that is composed of round cells; often absent in fine and naturally blond hair.
what is the medulla
51%
Carbon
Hydrogen bond
A weak, physical, cross-link side bond that is easily broken by water or heat.
Eumelanin
Provides natural dark brown to black color to the hair and is the dark pigment predominant in black and brunette hair.
catagen phase
The brief transition period between the growth and resting phases of a hair follicle. It signals the end of the growth phase.
what is the order of the the hair shaft
Cortex
Medulla
Cuticle
The five elements are and make up what
The five elements—carbon, oxygen, hydrogen, nitrogen, and sulfur—that make up human hair, skin, tissue, and nails.
disulfide bond
Strong chemical side bond that joins the sulfur atoms of two neighboring cysteine amino acids to create one cystine, which joins together two polypeptide strands like rungs on a ladder.
Melanin
The tiny grains of pigment in the cortex that give natural color to the hair.
What is the hair phases in order
the growing phase, anagen; the regressing phase, catagen; and the resting phase, telogen.