Physiology

Question 1

layers of the skin

Answer 1

epidermis
appendages
dermo-epidermal junction
dermis
sub-cutis layer

Question 2

what are the epidermal layers?

Answer 2

keratin layer
granular layer
prickle cell layer
basal layer

Question 3

what is the epithelium of the epidermis?

Answer 3

stratified squamous epithelium

Question 4

another name for the keratin layer?

Answer 4

stratum corneum

Question 5

what is the keratin layer made up of?

Answer 5

corneocytes and lamellar granules with lipids and keratinocytes

Question 6

what are corneocytes?

Answer 6

keratinocytes that have lost their nuclei

Question 7

what is the granular layer made up of?

Answer 7

flatten cells with keratohyalin granules (Odland bodies) with filaggrin and involucrin proteins

Question 8

prickle cell layer

Answer 8

polyhedral cells with desmosomes

Question 9

basal layer

Answer 9

cells with high metabolic rates and melanocytes

Question 10

role of melanocytes in the basal layer

Answer 10

absorb sunlight and converts tyrosine to melanin for pigmenting hair and skin

Question 11

what migrates from the basement membrane to the stratum corneum over 28 days?

Answer 11

keratinocytes

Question 12

what are keratinocytes involved in?

Answer 12

vitamin D production

Question 13

conditions where epidermal turnover control is lost?

Answer 13

cancer

psoriasis

Question 14

other cells in the epidermis

Answer 14

Langerhans cells (Birbeck granules)
merkel cells

Question 15

appendages in the skin

Answer 15

nails
hair
glands

Question 16

what are hairs in the skin attached to?

Answer 16

arrector pili

sebacous gland

Question 17

how are hairs pigmented?

Answer 17

melanocytes

Question 18

phases of hair growth

Answer 18

anagen (growing)
catagen (transitioning)
telogen (resting)

Question 19

three types of glands in the skin

Answer 19

1. sebaceous
2. apocrine
3. eccrine

Question 20

describe sebaceous glands

Answer 20

attached to hairs
hormone sensitive
produce sebum

Question 21

describe apocrine glands

Answer 21

present in axilla and perineum

androgen dependent

Question 22

describe eccrine glands

Answer 22

whole skin surface controlled by sympathetic nerves
ultrafiltration
thermoregulation

Question 23

cells that make up the dermis

Answer 23

connective tissue
fibroblasts
macrophages
mast cells
fibres
ground substances

Question 24

role of fibroblasts in the dermis

Answer 24

produce collagen

Question 25

fibre types in the dermis

Answer 25

collagen and elastin

Question 26

ground substance in the dermis

Answer 26

hyaluronic acid

Question 27

what does the dermis contain?

Answer 27

blood vessels
arrector pili
lymphatics
nerves (Pacinian, Meissner’s and autonomic)

Question 28

what is the sub-cutis layer made of?

Answer 28

fat (energy stores)

Question 29

roles of the skin

Answer 29

barrier
thermoregulation
immune defence
metabolism (vit D)
sensation