Glossary
A B C D E F G H I J K L M N Ñ O P Q R S T U V W X Y Z
Alopecia areata: Alopecia is characterised by the presence of hair loss in specific patches. It can extend as far as total loss of body hair and has a number of causes.
Androgenic alopecia: androgenic alopecia, or common baldness, is a consequence of androgens stimulating genetically susceptible hair follicles on the scalp, leading them to stop producing terminal hairs and start producing vellus hairs..
Alopecia universalis: complete loss of hair from the whole body.
Anagen: the growth phase of a hair follicle. It lasts 2 to 3 years.
Anagen efflivium: hair loss resulting from the sudden interruption of the active growth phase of the hair, such as that caused by radiation or chemotherapy.
Androgen: male hormone that stimulates the development and maintains the functions of secondary sex characteristics in males (e.g., growth of beard and hair, deeper tone of voice, muscle development, etc.). the most important androgen is Testosterone.
Autoimmune: autoimmune diseases and reactions appear when the body’s immunological system reacts against itself.
Autosomal dominant: autosomal is the name given to a gene or group of genes that are not situated in the sex chromosomes. If a genetic feature is dominant, it will always be expressed and will not be hidden by the opposite gene.
-
Bitemporal recession: expression describing the disappearance of hair from both temples.
Bulb: the bottom part of the hair follicle.
-
Catagen: transition phase of a hair follicle, which last approximately 2 weeks.
Cicatricial alopecia: alopecia caused by lesions to the hair follicles.
-
Dermic papilla: central part of the hair bulb.
Dermis: the thick layer of live tissue underneath the epidermis.
Desquamation: peeling or flaking of the surface of the skin.
DHT (Dihydrotestosterone): a natural compound deriving from Testosterone that is ultimately responsible for male pattern hair loss or common baldness.
Dystrophic: defective development.
-
Epidermic: related to the external layer of the skin.
Epithelial: belonging to or formed by the epithelium, which is a sheet of closely-bound cells in one or two layers, which cover the outer surface of the whole body.
Estradiol: the strongest oestrogenic hormone, secreted by the ovaries of mammals.
Exclamation mark hairs: this type of hair typically appears with alopecia areata. The hairs are broken, they are easily pulled out and they taper towards their proximal end.
-
Five-alpha-reductase: enzyme that catalyses the production of DHT, which is ultimately responsible for androgenic alopecia or common baldness.
-
Hair erector muscle: small involuntary muscle that runs from the surface of the dermis to the hair follicle, under the sebaceous gland.
Hair follicle: skin structure in which the hair is embedded.
Hirsutism: process caused by androgens in women, characterised by the excessive growth of male-type, terminal hair on the face, thorax and pubic region.
Hypertrichosis: excess of hair in areas where hair does not normally grow.
-
Keratin: protein found in hair and nails.
-
Lanugo: very fine hair that covers the body and limbs of human foetuses. It is most abundant towards the 28th week of gestation and is shed after 40 weeks.
-
Miniaturisation: term used to refer to the reduction in the size and diameter of the hair follicle and hair shaft during the process of hair loss.
Minoxidil: a peripheral vasodilator; it is used as a drug to treat hypertension and has properties that stimulate hair growth, thus preventing hair loss.
-
Non-cicatricial alopecia: alopecia that results from a primary disease that affects the hair follicles.
-
Occipital: relating to the back of the head.
Oestrogen: any of several hormones that induce oestrus, stimulate changes in the female reproductive organs and promote the appearance of secondary sex characteristics in females.
-
Parietal: belonging or relating to the walls of the skull; in the case of the scalp, parietal refers to the sides.
Polycystic ovary syndrome: disease in which the size of the two ovaries increases due to the presence of multiple cysts. It is often associated with infertility or excess hair growth.
-
Scalp flan surgery: hair replacement surgery that consists of stretching an area of the scalp that is covered with hair to cover a bald area.
Sebaceous gland: structure that produces grease in the follicle.
Seborrheic eczema: type of eczema found in the scalp and which is produced by a slight defect in the sebaceous glands. May be the cause of hair loss.
-
Telogen: resting phase of the hair follicle, which last approximately 2 weeks.
Telogen effluvium: hair loss characterised by a disproportionately high number of telogenic hairs falling out simultaneously. It is also called diffuse alopecia. May be caused by disease, stress or childbirth.
Terminal hair: thicker pigmented type of hair (unlike vellus hair).
Trichogram: study under a microscope of the hair bulbs of more than a certain number of hairs (usually 50) to determine the proportion of anagen and telogen hairs.
Trichotillomania (hair pulling): The habit of pulling one's hair out, which is very common in children and can be a cause of baldness.
-
Vellus hair: fine pale hair that grows on some parts of the body.
Vertex: the vertex of the scalp is the crown, where the hair grows in a circular form around the top of the head; this is the area that is most susceptible to hair loss.
- Siguenos en:
