Hair Loss: Glossary
Cobblestoning: "Plugs" that have not healed flush with the
skin and therefore have left the scalp lumpy. "Plugs" seldom heal flush with
the skin. Cobblestoning occurs in almost all "plug" procedures.
Cortex: The layer of the hair shaft that surrounds the
medulla and is filled with keratin fibers. The main structural part of the hair
fiber that accounts for most of its size and strength.
Crown: The highest part of the head.
Cuticle: The outer surface of hair, composed of overlapping
scales made of colorless keratin protein. It gives hair luster and shine and
also provides some of its strength.
Dermal Papilla: The dermal papilla is situated at the base
of the hair follicle. The dermal papilla contains nerves and blood vessels,
which supply glucose for energy and amino acids to make keratin. This structure
is extremely important in the regulation of hair growth since it has receptors
for both androgens and hair-promoting agents.
Dermis: One of the two layers of cells that form skin.
Specifically, it is the innermost layer.
Diazoxide: A drug that dilates blood vessels by opening
potassium channels and also promotes hair growth.
Dihydrotestosterone (DHT): Male hormone thought to be the
main cause for the miniaturization of the hair follicle and for hair loss. DHT
is formed when the male hormone testosterone interacts with the enzyme 5-alpha
Donor Site: Area where pieces of hair-bearing skin are
taken from during a hair transplant.
Double Blind Study: A scientific study where neither the
subjects nor the researchers know who specifically is receiving the drug of
treatment under study.
Dutasteride: A 5-alpha-reductase inhibitor medication by
GlaxoSmithKline. Dutasteride inhibits both type-I and type-II 5-alpha
Epidermis: The outer protective, nonvascular layer of the
Estrogen: The female hormone secreted primarily by the
Female Pattern Baldness (FPB): Progressive thinning of hair
throughout the entire head caused by genes, age, and hormones. It usually
develops at a much slower rate than male pattern baldness.
5-Alpha-Reductase: The chemical that is responsible for
transforming testosterone into dihydrotestosterone.
5-Alpha-Reductase Inhibitors: Prevent the body from
converting testosterone to dihydrotestosterone by blocking the action of the
enzyme 5-alpha reductase.
Finasteride: The generic name of the brand name drug
Proscar. Proscar is manufactured by Merck and is FDA approved for the treatment
of benign prostate enlargement. 1mg tablets of finasteride have been marketed
under the brand name Propecia as a treatment for hair loss. It is an
antiandrogen that blocks the formation of dihydrotestosterone by inhibiting the
enzyme 5-alpha reductase.
Flap: A type of hair replacement surgery in which a piece
of hair-bearing scalp is cut on three or four sides and transplanted onto bald
areas of the scalp. Follicle: A saclike structure just below the surface of
your scalp. It is the sheath within which hair grows.