Physiology Flashcards
what are the 5 functions of the skin?
barrier- both physical and chemical metabolism & detox: vitD synthesis thermoregulation: sweat glands immune defence: Langerhans cells sensory function: touch, pain etc
what are the layers of the skin
epidermis> dermoepidermal junction > dermis > sub-cutis + appendages (nails etc)
epidermis has __ layers
4
place the 4 layers of skin epidermis in order from outside to internal and their Latin name
keratin (stratum corneum)
granular layer (stratum granulosum)
prickle cell layer (stratum spinosum)
basal layer (stratum basale)
which of the 4 layers is…
- waterproof
- contains melanocytes
- has Odland bodies
- keratin layer
- basal layer
- granular layer
keratinocytes, melanosytes, langerhans cells, Merkel cells are 4 cells found in the ______
epidermal layer
____ are pigment producing dendritic cells derived from the neural crest and migrate to the skin
melanocytes
T/F: Eumelanin is yellow red pigment
F: Eumelanin is brown/black, phaeomelanin is yellow/red
MCR1 gene does what?
converts paheomelanin to eumelanin
describe Langerhans cells…
produced in bone marrow, found in prickle cell layer of epidermis, antigen presenting cells and circulate to LNs
responsible for skin immune system
Merkel cells are…
mechanoreceptors that are found in basal cell level
name 2 components of the dermis
any 2 from- collagen, hyaluronic acid, elastic fibres, chondroitin sulphate
appendages are found in the _____ dermis
reticular
name 3 cells found in the dermis
any 3 from; fibroblasts, macrophages, mast cells, lymphocytes, langerhans cells
DEJ function? (3 points)
- supports, anchors and adheres epidermis and dermis
- helps grow basal cells
- semi-permeable membrane so filters
what are the 3 skin glands and their function
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
T/F: oncogenesis induces cell division by mutation of RAS
T
tumour suppressors ____ cell division
inhibits
why is UV light cancerous?
causes clonal expansion of mutant p53 cells
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
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
how many skin types are there?
6
1= always burns
6= black skin
