Hair

Question 1

What structure surrounds

each hair & why is it important?

Answer 1

The Follicle; Its Epithelial Root Sheath provides the stem/germ cells for the growth of
the hair from the inner layer called the Internal Root Sheath.

Question 2

What is the hair matrix?

Answer 2

The hair matrix is the area in the Root Bulb (round base section of hair) where the
stem/germ cells divide, causing the growth of the hair. (These stem cells are made in
the Internal Root Sheath of the hair follicle & then move down into the hair matrix.)

Question 3

Which layers of the hair contain

hard keratin?

Answer 3

The first two layers of the hair, the Cuticle and Cortex, contain hard keratin.

Question 4

What are arrector pili?

Answer 4

Arrector Pili are tiny muscles attached to each hair that contract in response to cold
temperature (or even fear), causing the hair to stand straight up. The skin puckers,
forming “goose bumps,” when these muscles contract.

Question 5

What part of the follicle or hair
itself is the only area that is
not made of epithelial cells?

Answer 5

The only part of the hair and hair follicle that is not made of epithelial cells is the outer
layer of the Hair Follicle, called the Dermal Root Sheath or Connective Tissue Root
Sheath. It is white because it is made of collagen.