Structure
The lowest part of a hair strand; the thickened, club-shaped structure that forms the lower part of the hair root.
Hair bulb
Units that are joined together end-to-end, like pop beads, by strong chemical peptide bonds.
Amino acids
Also known as the growth phase, this is when new hair is produced.
Anagen phase
This results from the loss of the hair's natural melanin pigment. It's the technical term for gray hair.
Canities
It measure the number of individual hair strands on one square inch of scalp.
Hair density
Hair cuticle
The small, involuntary muscle in the base of the hair follicle. It can result in goose bumps when it contracts.
Arrector pili muscle
The brief transition period between the growth and resting phases of a hair follicle that also signals the end of the anagen phase.
An autoimmune disorder that causes the affected hair follicles to be mistakenly attacked by a person's own immune system.
Alopecia areata
The ability of the hair to stretch and return to its original length without breaking. It's an indication of the strength of the side bonds.
Hair elasticity
The tube-like depression or pocket in the skin or scalp that contains the hair root.
Hair follicle
A fibrous protein core formed by elongated cells containing melanin pigment. It is the middle layer of the hair.
Cortex
The final phase in the hair cycle, also known as resting phase, and lasts until the fully grown hair is shed.
Telogen phase
This is a condition of abnormal growth of hair and is also known as hirsuties.
Hypertrichosis
The ability of the hair to absorb moisture. It's directly related to the condition of the cuticle layer.
Hair porosity
A fibrous protein that grows from cells originating within the hair follicle.
Keratin
A small, cone-shaped elevation located at the base of the hair follicle that fits into the hair bulb. Sometimes called the "mother" of the hair.
Dermal papilla
Short, fine, unpigmented, and downy hair that appears on the body; also known as lanugo hair.
Vellus hair
The infestation of the hair and scalp with head lice.
Pediculosis Capitis
The thickness or diameter of the individual hair strand; classified as coarse, medium, or fine.
Hair texture
Process by which newly formed cells in the hair bulb mature, fill with keratin, move upward, lose their nucleus, and die.
Keratinization
A strong, chemical, side bond that that joins the sulfur atoms of two neighboring cysteine amino acids to create one cystine.
Disulfide bond
The long, coarse, pigmented hair found on the scalp, legs, arms, and bodies of males and females.
Terminal hair
The technical term for classic dandruff that is characterized by scalp irritation, large flakes, and an itchy scalp.
Pityriasis capitis simplex
Hair flowing in the same direction, resulting from follicles sloping in the same direction.
Hair Stream