Chapter 7

Question 1

Sebaceous glands are attached to the hair follicle. They produce a substance called sebum , also known as oil. Sebum lubricates the hair and skin.

Answer 1

Sebaceous glands

Question 2

The hair follicle is a tube-like structure in the skin or scalp that surrounds the hair root and anchors the hair in the skin. Hair follicles are not found on the palms of the hands or the soles of the feet.

Answer 2

Hair follicle

Question 3

The hair bulb is located at the base of the follicle. It has a bulb shape and contains living cells that will form the hair strand.

Answer 3

Hair bulb

Question 4

The dermal papilla (plural: dermal papillae), also called hair papilla, is a cone-shaped elevation at the base of the hair bulb. It contains blood vessels that supply nutrients that allow the hair to grow.

Answer 4

Dermal papilla

Question 5

The arrector pili muscle is an involuntary muscle in the dermis that attaches to the hair follicle. When the arrector pili contracts, the hair strand stands up, causing goosebumps.

Answer 5

Arrector pili muscle

Question 6

The hair cuticle is the hair’s outermost layer. It is formed from cells that overlap, similar to shingles on a roof. The cuticle protects the cortex. In healthy hair, the cuticle lies flat, but during chemical services, it will soften and swell, allowing the chemicals to penetrate the cortex

Answer 6

Hair cuticle

Question 7

The cortex is the fibrous protein layer of the hair. It is responsible for hair’s strength, elasticity, and color, and contributes to about 90 percent of hair’s weight.

Answer 7

Cortex

Question 8

The medulla is also known as the hair’s pith or core. Not all hair types have a medulla. Generally, coarse hair has a medulla, while fine hair doesn’t. Beard hair always contains a medulla.

Answer 8

Medulla

Question 9

Hair is composed primarily of a protein called keratin. The living cells that form the hair are found in the hair bulb. These cells go through a process called keratinization .

Answer 9

Keratinization

Question 10

The major elements that make up human hair are carbon, oxygen, hydrogen, nitrogen, and sulfur. They are referred to as the COHNS elements

Answer 10

COHNS elements

Question 11

form the building blocks of protein; link together end to end like pop beads by strong, chemical peptide bonds (end bonds) to form the polypeptide chains that comprise proteins

Answer 11

Amino acids

Question 12

also known as an end bond; chemical bond that joins amino acids to each other, end-to-end, to form a polypeptide chain

Answer 12

peptide bond

Question 13

long chain of amino acids linked by peptide bonds

Answer 13

polypeptide chain

Question 14

The cortex is made up of millions of polypeptide chains, which are cross-linked like a ladder’s rungs by three types of side bonds : hydrogen, salt, and disulfide bonds