Trichology

Question 1

Define Trichology

Answer 1

Scientific study of hair and its diseases and care

Question 2

What two parts is a mature human strand of hair divided into?

Answer 2

The hair root and the hair shaft

Question 3

Define hair root

Answer 3

Is the part of hair located below the surface of the epidermis

Question 4

What is the hair shaft

Answer 4

The portion of the hair that projects above the epidermis

Question 5

What are the 5 main structures of the hair root

Answer 5

Hair follicle, hair bulb, dermal papilla, arrector pili muscle, sebaceous gland, and sebaceous oil glands

Question 6

What is a hair follicle

Answer 6

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

Question 7

Where is the hair follicle on the body

Answer 7

Distributed all over the body except palms and soles

Question 8

What is the hair bulb

Answer 8

It’s the lowest part of a hair strand. A thickened club shaped structure that forms the lower part of the hair root.

Question 9

What is the dermal papillae

Answer 9

Contains the blood and nerve supply that provides nutrients needed for hair growth

Question 10

What is the erector pili muscle

Answer 10

Small involuntary muscle in the base of the hair follicle

Question 11

What does the erector pili muscle do

Answer 11

Strong emotions or a cold sensation cause it to contract which makes the hair strand straight up?

Question 12

Is the sebaceous glands

Answer 12

Oil glands in the skin that are connected to the hair follicles. The glands secrete a fatty or oily substance called sebum. Sebum lubricates the skin

Question 13

What are the three main layers of the hair shaft

Answer 13

Cuticle, cortex, medulla

Question 14

Define hair cuticle

Answer 14

Outermost layer of the hair

Question 15

What does the hair cuticle look like

Answer 15

Single overlapping layers of transparent scale like cells that look like shingles on a roof

Question 16

What does the hair cuticle provide

Answer 16

It provides a barrier that protects the inner structure of the hair as it lies tightly against the cortex

Question 17

What is the hair cuticle responsible for

Answer 17

Responsible for creating the shine and smooth silky feel of healthy hair

Question 18

What is the cortex

Answer 18

Is the middle layer of the hair. It’s a fibrous protein core formed by cells containing melanin pigment. The elasticity of the hair and its natural color are the result of the unique protein structures located within the cortex

Question 19

What percent of total weight of hair comes from the cortex

Answer 19

About 90

Question 20

What is the medulla

Answer 20

The innermost layer of the hair. Generally only thick hair contains a medulla

Question 21

What is melanin

Answer 21

Tiny grains of pigment in the cortex that give natural color to the hair

Question 22

What is the melanin

Answer 22

Tiny grains of pigment in the cortex that give natural color to the hair

Question 23

What are the two types of melanin

Answer 23

Eumelanin and pheomelanin

Question 24

What is eumelanin

Answer 24

The melanin that lends black and brown colors to hair

Question 25

What is pheomelanin

Answer 25

Red yellow pigment

Question 26

What are the two main types of hair on the body

Answer 26

Vellum and terminal hair

Question 27

Define vellus hair

Answer 27

Short fine unpgmented and downy hair

Question 28

What does vellus hair do

Answer 28

Helps with the evaporation of perspiration

Question 29

Define terminal hair

Answer 29

Long, coarse, pigmented hair found on the scalp, legs, arms, and bodies of males and females

Question 30

What are the 3 phases of the hair growth cycle

Answer 30

Anagen, catagen, telogen

Question 31

Define the anagen phase

Answer 31

(AKA growth phase) new hair is produced. During this phase, hair is produced. During this phase hair cells are produced faster than any other call in the human body.

Question 32

Define catagen phase

Answer 32

The brief transition period between the growth and resting phases of a hair follicle. The resting follicle canal shrinks and detaches from the dermal papilla. The hair bulb disappears and the shrunken root end forms a rounded club

Question 33

How long does the catagen phase last?

Answer 33

1-2 weeks

Question 34

Define the telogen phase

Answer 34

(AKA the resting phase) is the final phase in the hair cycle and lasts until the fully grown hair is shed.

Question 35

How long does the telogen phase last

Answer 35

3-6 months

Question 36

How often does the growth cycle repeat itself

Answer 36

Once every 4-5 years