Trichology

Question 1

Trichology

Answer 1

The study of hair

Question 2

Hair is chiefly composed of the protein..

Answer 2

Keratin

Question 3

Where is hair?

Answer 3

Everywhere except:
Soles of the feet
Palm of hands
Nipples
Some areas of the genitals
Mucous membrane of lips
Navel

Question 4

Where is hairs heaviest concentration?

Answer 4

Scalp
Axillary organ
Arms
Legs
On and around genitals

Question 5

Hair growth occurs in cycles consisting of 3 phases..

Answer 5

Anagen (growth phase)
Catagen (transitional phases)
Telogen (resting phase)

Question 6

Anagen

Answer 6

Most hair is growing at any given time, each hair spends several years in this phase

Question 7

Catagen

Answer 7

Over a few weeks, hair growth slows and the hair follicle shrinks

Question 8

Telogen (resting phase)

Answer 8

Over months, hair growth stops and the old hair detaches from the hair follicle. New hair begins the growth phase, pushing the old hair out.

Question 9

What is the average rate of hir growth?

Answer 9

Around 1/2 inch per month and 5 inches per year

Question 10

3 hair conditions

Answer 10

Alopecia areata
Dandruff
Dead lice

Question 11

Alopecia Areata

Answer 11

Round patches of total hair loss, usually from the scalp, the cause of alopecia is unknown; the hair usually grows back.

Question 12

Dandruff

Answer 12

Ongoing mild inflammation of the scalp, resulting in scaly skin that may be itchy and flake off. May also effect the ear and face.

Question 13

Head lice

Answer 13

Tiny insects that live on the scalp and feed on the blood. Young children are more susceptible. Only spread through close contact

Question 14

Hair DNA testing

Answer 14

Hair follicles contain DNA; hair can be tested to establish paternity, of as evidence in a crime investigation

Question 15

Functions of the hair:

Answer 15

Protection- comparatively little protective value, however eyelashes, eyebrows, and hair inside nostrils and ears, and those around above oral orifices have useful functions

Sensory reception- all hair follicles are surrounded by sensory nerves, which respond to pressure on the shaft

Question 16

Factors influencing hair growth:

Answer 16

1. Race
2. Heredity
3. Age
4. Body region
5. Sex
6. Stress level
7. Hormones
8. Medication
9. Nutrition
10. Season of the year
11. Illness

Question 17

Hair shaft

Cuticle, cortex, medulla

Answer 17

The part of the hair above the scalp or skin - emerging from the follicle out of the follicular pore

Question 18

Cuticle

Answer 18

-Outer layer of hair
-Single layer of over lapping scales
-Translucent
FUNCTION:
Holds cortex together
Gives the hair its elasticity

Question 19

Cortex

Answer 19

• melanin granules are found in this layer (melanin gives hair its colour)
• in absence of melanin the hair becomes dull, white, translucent
• composed of more than one layer of keratinized cells

Question 20

Medulla

Answer 20

• Centre of hair shaft
• Composed of large, loosely connected horny cells
• May be absent, as in very fine hairs

Question 21

Hair follicle

Answer 21

Outer root sheath: lies furthest from the hair shaft. A bulge in the outer root sheath at the intersection of attractor pili muscles, houses several types of stem cells, which supply the hair follicle with new cells.

Inner root sheath: lies closest to the hair shaft. Consists of 3 layers of cells. The cells interlink to help secure the hair within the hair follicle.

Question 22

Hair root

Answer 22

• The part of the hair below the skin.

- the cells within the matrix reproduce new cells by mitosis

Question 23

Hair bulb

Answer 23

• Inferior and swollen part of the root

- Base of the hair follicle where new hair develops

Question 24

Nerve endings

Answer 24

A collar of sensory nerve endings from a single nerve encircles the follicle about 1/2 way between base of follicle and skin surface.

Question 25

Different changes in hair growth

Answer 25

Puberty
Pregnancy
Menopause

Question 26

Where is most hair pigment

Answer 26

In the cortex

Question 27

Melanocytes

Answer 27

Cells which produce melanin.

If pigment has disappeared, hair looks grey or white. The amount of melanin is genetically determined.

Question 28

Red hair

Answer 28

Red hair is the product of a separate gene.

True red heads possess only special red pigment.