phase 3: hair removal and infection control

What is the scientific study of hair and its diseases called?

Trichology

What is the hair follicle?

A mass of epidermal cells forming a small tube or canal.

What does the pilosebaceous unit contain?

The hair follicle and its appendages: hair root, hair bulb, hair papilla, hair shaft, arrector pili muscle, and sebaceous glands.

What is the hair root?

The part of hair located below the skin’s surface that anchors hair to skin cells.

What is the hair bulb?

A thick, club-shaped structure made from epithelial cells that surrounds the papilla; forms the lower part of the follicle.

What is the hair papilla?

A cone-shaped elevation of connective tissue at the base of the follicle containing capillaries and nerves that fit into the bulb.

What is the hair shaft?

he portion of hair located above the surface of the skin.

What does the sebaceous gland do?

Secretes sebum, a waxy substance that lubricates the skin and hair, keeping them soft, supple, and waterproof.

What is lanugo hair?

Soft, downy hair found on a fetus that sheds after birth and is replaced by vellus or terminal hair.

What is vellus hair?

Fine, short “peach fuzz” hair found on areas not covered by coarse terminal hair (like women’s cheeks)

What is terminal hair?

Long, coarse hair found on the scalp, brows, lashes, genitals, arms, and legs.
What causes hair growth? Activity of cells in the basal layer within the hair bulb.

What are the three stages of the hair growth cycle?

Anagen, Catagen, and Telogen.

What happens during the anagen phase?

It’s the growth phase when new keratinized cells are produced in the follicle.

What happens during the catagen phase?

The transition phase where mitosis stops, the hair detaches from the papilla, and the follicle collapses upward.

What happens during the telogen phase?

The resting phase where the club hair moves up the follicle and sheds naturally.

What is hypertrichosis?

Excessive growth of terminal hair in areas that normally grow only vellus hair.
What is hirsutism? Excessive hair growth on the face, chest, underarms, and groin (especially in women) caused by excess male androgens.

What’s the difference between temporary and permanent hair removal?

Temporary removal requires repeated treatments; permanent removal destroys the papilla, preventing regrowth.

What is depilation?

Removing hair at or near the skin’s surface (e.g., shaving or chemical depilatories like Nair and Veet).

What is epilation?

Removing hair from the bottom of the follicle by detaching it from the papilla (methods include tweezing, waxing, sugaring, and threading).

What is threading (banding)?

A method using twisted cotton thread guided across the skin to snag and remove unwanted hairs.

What is sugaring?

A natural hair removal method using a sugar, lemon juice, and water paste applied against hair growth and removed in the direction of growth.

What is waxing?

The primary hair removal method using hard or soft wax applied to the skin to pull out hair from the follicle.

What are the methods of permanent hair removal?

Electrolysis, Laser Hair Removal, and IPL (Intense Pulsed Light).

Which method is the only one recognized as truly permanent?

Electrolysis.
What are the three modalities of electrolysis? Thermolysis, Galvanic Electrolysis, and the Blend.