Properties Of The Hair And Scalp Flashcards
Alopecia
Abnormal hair loss. (3 common types: androgenic, areata, and postpartum)
Alopecia areata
An autoimmune disorder that causes the effected hair follicles to be mistakenly attacked by a persons own immune system.
Alopecia totalis
Hair disorder that begins with one or more small, round or smooth bald patches on the scalp and can progress to total scalp hair loss.
Alopecia universalis
Complete body hair loss.
Trichology
The scientific study of hair and its diseases.
Hair root
The part of the hair located below the surface of the epidermis (outer layer of the skin).
Hair shaft
Portion of the hair that projects above the epidermis.
Hair follicle
Is the tube-like depression or pocket in the skin or scalp the contains the hair root. The follicle extends downward from the epidermis into the dermis (the inner layer of skin) where it surrounds the dermal papilla.
Hair bulb
The lowest part of a hair strand. It is the thickened, club-shaped structure that forms the lower part of the hair root.
Dermal papilla
Small cone shaped elevation located at the base of the hair follicle that fits into the hair bulb. (“Mother of the hair” because it contains the blood and nerve supply the provides nutrients for hair growth).
Arrector pili
small, involuntary muscle in the base of the hair follicle. (goose bumps are caused by the contracting of this muscle).
Sebaceous glands
Oil glands in the skin that are connected to the hair follicles. These glands secrete fatty or an oily substance called sebum. Sebum lubricates the skin.
3 main layers of the hair shaft
Hair cuticle, Cortez and medulla.
Hair cuticle
The outermost layer of the hair.it consists of transparent, scale-like cells that look like shingles on a roof. It protects the inner structure of the hair.
Cortex
Middle layer of the hair. It is a fibrous protein core formed by elongated cells containing melanin pigment.
Medulla
The innermost layer of the hair and is composed of round cells.
Keratinization
The process in which hair follicles mature. As the newly cells mature, they fill up with a fibrous protein called keratin.
COHNS elements
Major elements that make up the human hair. Carbon, oxygen, hydrogen, nitrogen, and sulfur.
Vellus hair (lanugo hair)
Short, fine unpigmented and downy hair that appears on the body.
Terminal hair
Long, coarse, pigmented hair found on the scalp, legs, arms and bodies of males and females. Coarser than vellus hair and with the exception of grumpy hair it is pigmented. (Regular hair)
Anagen phase (growth phase)
New hair is produced during this phase of the growth cycle of hair.
Catagen phase
The brief transition period between the growth and resting phases of a hair follicle. It signals the end of the anagen phase. During this phase the follicle canal shrinks and detaches from the dermal papilla.
Telogen phase (resting phase)
Final phase in the hair cycle and lasts until the fully grown hair is shed. The hair is either shed during the telogen phase or remains in place until the next anagen phase, when the new hair growing in pushes it out.
Canities
Technical term for gray hair. Canities results from the loss of the hair’s natural melanin pigment. (Two types: congenital and acquired)
Hypertrichosis
A condition of abnormal growth of hair.growth of terminal hair in areas of the body that normally grow only vellus hair. (Ex: mustache or beard)
Trichoptilosis
Technical term for split ends.
Trichorrhexis nodosa
Technical term for knotted hair.
Monilethrix
Technical term for beaded hair. Hair breaks easily between the beads or nodes.
Fragilitas crinium
Technical term for brittle hair.
Pityriasis
Technical term for dandruff which is characterized by the excessive production and accumulation of skin cells.
Pityriasis capitis simplex
Technical term for classic dandruff that is characterized by scalp irritation, large flakes and itchy scalp.
Pityriasis steatoides
More sever case of dandruff characterized by an accumulation of greasy or waxy, mixed with sebum, that stick to the scalp in crusts.
Tinea
Technical term for ringworm. Characterized by itching, scales and sometimes painful circular lesions.
Tinea favosa (tinea favus)
Characterized by dry, sulfur-yellow, cup-like crusts on the scalp called scutula.
Scutula
Dry, sulfur-yellow, cup-like crusts in the scalp. Scutula has a distinctive odor.
Scabies
Highly contagious skin disease caused by a parasite called a mite that burrows under the skin.
Pediculosis capitis
The infestation of the hair and scalp with head lice.
Staphylococci
Bacteria that infect the skin or scalp. (Two most common types: furuncles and carbuncles)
Furuncle
Technical term for a boil, an acute localized bacterial infection of the hair follicle that produces constant pain.
Carbuncle
Is an inflammation of the subcutaneous tissue caused by staphylococci. Similar to furuncle but its larger.
Hair texture
The thickness or diameter of the individual hair strand. Can be classified as coarse, medium or fine.
Hair density
Measures the number of individual hair strands on 1 square inch of scalp. (Average hair density is about 2,200 hairs per 1 square inch)
Hair porosity
The ability of the hair to absorb moisture. The degree of porosity is directly related to the condition of the cuticle layer.
Hydrophobic
Healthy hair with a compact cuticle layer is naturally resistant to being penetrated by moisture.
Hydrophilic
Porous hair that has a raised cuticle layer that easily absorbs moisture.
Hair elasticity
The ability of the hair to stretch and return to its original length without breaking.
