Chapter 5

Hair Structure

100

Provide the hair with natural oils

What are sebaceous glands?

200

Responsible for supplying the hair with oxygen-rich blood, nerves, and keratin protein cells that nourish the hair, and stimulate growth and regeneration.

What is the dermal papilla?

300

How many follicles are there on a human head?

What is about 100,000-150,000?

400

Pigmented hair found on the scalp, arms, legs, nose, and ears. This hair is coarser than vellus hair, although it varies in texture, color, and length.

What is terminal hair?

500

Small, involuntary muscle attached to the underside of a hair follicle. Fear or cold causes this muscle to contract and makes hair stand up straight, giving the skin the appearance of "goosebumps."

What is the arrector pili muscle?

Chemical Composition

100

Cross section of straight hair is

What is round?

200

Thickest part of the hair shaft. Takes almost 90 percent of the weight of the shaft.

What is the cortex?

300

Name the 5 elements that make up the amino acids that create the protein of the hair fiber.

What is carbon, oxygen, hydrogen, nitrogen, and sulfur?

400

A strong, chemical side bond, that can be broken by thio perms and thio relaxers, hydroxide relaxers, and extreme heat.

What are disulfide bonds?

500

Hydrogen bonds are side bonds that are weak and physical and broken by water or heat. How are they reformed?

What is drying or cooling?

Hair Textures

100

This hair configuration feels coarse or rough to the touch and may have a zigzag pattern.

What is wiry?

200

This hair configuration is referred to as "cottony"

What is kinky?

300

This hair configuration requires repeated moisture and hydration applications and oil for sheen.

What is tight coils?

400

This hair configuration does not reflect light and can feel dry to the touch.

What is tight curls?

500

This hair type has average density, requires low-pH products to close cuticle and has limited volume.

What is soft waves?

Hair Properties

100

True or false: the measurement from the top of your ponytail to the bottom is your diameter of the hair.

What is false?

200

Another word for high porosity.

What is hypophilic?

300

Curl configuration and diameter of the strand combine to create what?

What is texture?

400

Elasticity refers to what two things?

What is the ability to stretch and return to its original shape AND size?

500

Name the ideal diameter, porosity, and elasticity and why.

What is medium diameter so it has strength but not rough, normal porosity so it absorbs moisture well and doesn't lose it easily, and good elasticity so it is able to be handled without breaking?

Hair Growth Cycles

100

This is known as the transition phase.

What is catagen?

200

How many hairs on average are shed in a day?

What is 50-100?

300

The average range of healthy hair growth rate.

What is 1/4-1/2 inch?

400

Why people don't become bald during the telogen stage.

What is the individual growth cycle of each hair?

500

At any given time this range of percentage of the hair is in anagen.

What is 70-90 percent?