Hair cuticle
Outermost layer of the hair; consisting of a single, overlapping layer of transparent, scale-like cells that look like shingles on the root. Provides a barrier that protects the inner structure of the hair as it lies tightly against the cortex. Responsibl
Dermal papilla
Small cone-shaped elevation located at the base of the hair follicle that fits into the hair bulb. Contains the blood and nerve supply that provides the nutrients needed for hair growth.
Sebum
A fatty or oily substance secreted by the sebaceous glands that lubricates the skin.
Hair cortex
Middle layer of the hair; a fibrous protein core formed by elongated cells containing melanin pigment. About 90% of the hair comes from here. Elasticity of the hair and its natural color are the result of unique protein structures located in this. Changes
COHNS
Elements; carbon, oxygen, hydrogen, nitrogen and sulfur. Make up human hair, skin, tissue and nails.
Amino acids
Units that's are joined together end-to-end like pop beads by storing, chemical peptide bonds (end bonds) to form the polypeptide chains that comprise proteins.
Salt bonds
A weak, physical, cross-link side bond between adjacent polypeptide chains. These depend oh pH so they are easily broken by strong alkaline or acidic solutions. Account for about 1/3 of the hairs overall strength.
Lanthionine bonds
The bonds created when disulfide bonds are broken by hydroxide chemical hair relaxers after the relaxer is rinsed from the hair.
Pheomelanin
The lighter pigment that provides natural colors ranging from red and ginger to yellow and blond tones.
Lanugo hair
Aka vellum/vellus hair; Short, fine, unpigmented and downy hair that appears on the body with the exception of the palms of the hands and the soles of the feet. Almost never has a medulla. Commonly found on infants.
Telogen phase
Aka resting phase; final phase in the hair cycle hat lasts until the fully grown hair is shed.
Anagen phase
Aka growth phase; phase during which new hair is produced.
Alopecia totails
Total loss of hair scalp
Trichoptilosis
Technical term for split ends, only way to remove is by cutting.
Fragilitas crinium
Technical term for brittle hair
Malassezia
Naturally occurring fungus that is present on all human skin, but is responsible for dandruff when it grows out of control.
Pityriasis
Technical term for dandruff; characterized by excessive production and accumulation of skin cells.
Hair texture
Thickness or diameter of the individual hair strand
Pityriasis Capitis Simplex
Technical term for classic dandruff; characterized by scalp irritation, large flakes, and itchy scalp.
Pediculosis capitis
Infestation of the hair and scalp with head lice.
Trichoptilosis
Technical term for split ends
Trichorrhexis Nodosa
Technical term for knotted hair; it is characterized by brittleness and the formation of modular swellings along the hair shaft.
Catagen phase
The brief transition between the growth and resting phases of a hair follicle. It signals the end of the growth phase.