Chapter 11 Properties of the Hair & Scalp

Name three different hair properties for which the cortex is responsible.

1.) Elasticity 2.) Natural hair coloring 3.) Weight

What are the three main layers of the hair shaft?

1.) Hair cuticle 2.) Cortex 3.) Medulla

What percentage of the total weight of hair comes from the cortex?

90 percent

Polypeptide chain

A long chain of amino acids linked by peptide bonds

Which muscle causes goose bumps when it contracts due to strong emotions or a cold sensation?

Arrector Pili Muscle

The lowest part of the hair strand is called the hair ____.

Bulb

Together, the five elements that make up human hair are referred to as the _____ elements to help people remember them; they are also found in the ___ and the ____.

COHNS, Skin, Nails

In what layer of the hair do changes involving oxidation hair coloring, wet setting, thermal styling, permanent waving, and chemical hair relaxing take place?

Cortex

Which part of the hair root contains the blood and nerve supply that provides the nutrients needed for hair growth?

Dermal papilla

All hair has three layers of the hair shaft.

False

More than one hair will never grow from a single follicle

False

The outermost layer of the hair is the ___

Hair cuticle

A mature strand of human hair is divided into two parts: the ___, located below the surface of the epidermis, and the ______, the portion of the hair that projects above the epidermis.

Hair root, Hair shaft

Describe the hair cuticle layer.

It consists of a single overlapping layer of transparent, scale-like cells that look like shingles on a roof. It provides a barrier that protects the inner structure of the hair as it lies against the cortex.

The _____ is the innermost layer of the hair and is composed of round cells.

Medulla

Which layer of the hair is the cortex?

Middle

Hair is composed of _____ that grows from cells originating within the hair follicle.

Protein

If you hold the end of a single strand of hair in one hand and then grasp it between the thumb and forefinger of the other hand and move them down the hair shaft, the hair will feel ______.

Rough

The sebaceous glands secrete a fatty or an oily substance called ____, which lubricates the skin.

Sebum

Dermal papilla

Small, cone-shaped elevation located at the base of the hair follicle that fits into the hair bulb

Arrector pili muscle

Small, involuntary muscle in the base of the hair follicle

All professional hair services must be based on a thorough understanding of the growth, ____, and composition of hair.

Structure

Describe what a healthy cuticle layer protects.

The hair from penetration and prevents damage to hair fibers

Sebaceous glands

The oil glands in the skin that are connected to the hair follicles

Helix

The spiral shape of a coiled protein

Peptide bond

The strong, chemical bond that joins amino acids

Hair bulb

The thickened, club-shaped structure that forms the lower part of the root

Hair Follicle

The tube-like depression or pocket in the skin or scalp that contains the hair root

Why must oxidation hair colors, permanent waving solutions, and chemical hair relaxers have an alkaline pH?

To penetrate the cuticle layer because a high pH swells the cuticle and causes it to life and expose the cortex

___________ is the scientific study of hair and its diseases and care, which come from the Greek words _____, meaning "hair," and ____, meaning "the study of."

Trichology, Trichos, Ology

All male beard hair contains a medulla.

True

Hair is a living thing

True

The medulla is involved in salon services.

True

Amino Acids

Units that are joined together and make up proteins

List the main elements that make up human hair and their percentage in normal hair.

a.) Carbon 51% b.) Oxygen 21% c.) Hydrogen 6% d.) Nitrogen 17% e.) Sulfur 5%

Hair follicles are distributed all over the body, with the exceptions of:

a.) The palms of the hands b.) soles of the feet

List below why it is important for a cosmetologist to study and understand the properties of the hair and scalp.

a.) You need to know how and why hair grows and how and why it falls out in order to be able to differentiate between normal and abnormal hair loss. b.) knowing what creates natural color and texture is a vital part of being able to offer a variety of chemical services to clean. c.) Spotting and unhealthy scalp condition that could be harboring a communicable disease or even be causing permanent hair loss is a way to aid your client in caring for their scalp and their hairs well being.

The maturation of these cells is a process called ______

keratinization