Physiology

Question 1

what are the 5 functions of the skin?

Answer 1

barrier- both physical and chemical
metabolism & detox: vitD synthesis 
thermoregulation: sweat glands
immune defence: Langerhans cells
sensory function: touch, pain etc

Question 2

what are the layers of the skin

Answer 2

epidermis> dermoepidermal junction > dermis > sub-cutis + appendages (nails etc)

Question 3

epidermis has __ layers

Answer 3

4

Question 4

place the 4 layers of skin epidermis in order from outside to internal and their Latin name

Answer 4

keratin (stratum corneum)
granular layer (stratum granulosum)
prickle cell layer (stratum spinosum)
basal layer (stratum basale)

Question 5

which of the 4 layers is…

1. waterproof
2. contains melanocytes
3. has Odland bodies

Answer 5

1. keratin layer
2. basal layer
3. granular layer

Question 6

keratinocytes, melanosytes, langerhans cells, Merkel cells are 4 cells found in the ______

Answer 6

epidermal layer

Question 7

____ are pigment producing dendritic cells derived from the neural crest and migrate to the skin

Answer 7

melanocytes

Question 8

T/F: Eumelanin is yellow red pigment

Answer 8

F: Eumelanin is brown/black, phaeomelanin is yellow/red

Question 9

MCR1 gene does what?

Answer 9

converts paheomelanin to eumelanin

Question 10

describe Langerhans cells…

Answer 10

produced in bone marrow, found in prickle cell layer of epidermis, antigen presenting cells and circulate to LNs
responsible for skin immune system

Question 11

Merkel cells are…

Answer 11

mechanoreceptors that are found in basal cell level

Question 12

name 2 components of the dermis

Answer 12

any 2 from- collagen, hyaluronic acid, elastic fibres, chondroitin sulphate

Question 13

appendages are found in the _____ dermis

Answer 13

reticular

Question 14

name 3 cells found in the dermis

Answer 14

any 3 from; fibroblasts, macrophages, mast cells, lymphocytes, langerhans cells

Question 15

DEJ function? (3 points)

Answer 15

1. supports, anchors and adheres epidermis and dermis
2. helps grow basal cells
3. semi-permeable membrane so filters

Question 16

what are the 3 skin glands and their function

Answer 16

sebaceous: moisture loss. produce sebum and found in face and chest
apocrine: produce oily fluid. pits and perineum, androgen dependent
eccrine: filters and cools skin, supplied by sympathetic nervous system

Question 17

T/F: oncogenesis induces cell division by mutation of RAS

Answer 17

T

Question 18

tumour suppressors ____ cell division

Answer 18

inhibits

Question 19

why is UV light cancerous?

Answer 19

causes clonal expansion of mutant p53 cells

Question 20

UVB & UVA- match with true facts
direct DNA damage, indirect oxidative damage, absorbed by ozone layer (medium wave), not absorbed by ozone (long wave), repaired by BER, repaired by NER

Answer 20

UVB: direct DNA damage, absorbed by ozone layer (medium wave), repaired by NER

UVA: indirect oxidative damage, not absorbed by ozone (long wave), repaired by BER

Question 21

how many skin types are there?

Answer 21

6
1= always burns
6= black skin