skin P1 Flashcards
what are the functions of the skin?
- protect
- excrete salts, water, and organic waste by integumentary glands
- maintain main body temp
- produce melanin
- produce keratin
- synthesize vitamin D
- store lipids
- detect touch. pressure, pain, and temp stimuli
what are the 3 primary layers of the skin called
- epidermis
2, dermis
3, hypodermis
describe the epidermis layer (functions etc…)
- is the outer layer of skin
- is a stratified barrier
- mostly made of keratinocytes
- has no blood circulation
describe the dermis layer (functions etc…)
- helps the skin stay together
- is alive/has blood circulation
- has 7 layers
- protein fibres for strength
- is vascular
describe the hypodermis layer (functions etc…)
- is the lowest layer
- subcutaneous ( not the skin )
- adipose tissue (fats are)
- these fats are mobilised in starvation
with epithelial tissue, what does ‘simple’ and ‘stratified’ mean
simple = single/ 1 layer stratified = stacked/ multiple layers
what does squamous, cuboidal and columnar look like
squamous = squashed cuboidal = cube columnar = columns
how many layers are in the epidermis
4 layers
what are the name of the layers in the epidermis (top to bottom)
stratum corneum
stratum granulosum
stratum spinosum
stratum basale
describe the stratum corneum (horny layer)
has dead, dried-out hard cells that dont have a nuclei.
flakes off the body
are formed in horns
describe the stratum granulosum layer
it dehydrates the cells that are being pushed towards the surface
cross-links the keratin fibres
waxy material is secreted into intercellular spacing to fill the gaps
describe the stratum spinosum layer
has intercellular bridges called desmosomes
cells become increasingly flattened as they move up
describe the stratum basale layer
are tall (columnar) regenerative cells
as the cell divides, the daughter cell migrates upwards to replenish the layer above
never runs out
what are hemidesmosomes?
they help anchors the stratum basale to the dermis
what are desmosomes
they anchor neighbouring cells in the epidermis
true or false, the stratum corneum be completely removed
true
how many layers are in thick skin
5 layers
what is the extra layer in thick skin called
stratum lucidum
what are the 2 layers under the dermis called
- papillary layer
- reticular layer
describe the papillary layer
it consists of highly vascularised tissue with is used for nourishment
describe the reticular layer
its a ‘mesh-like’ structure of collagen and elastin fibres
- for strength
what do both the papillary and reticular layer contain
- blood vessels
- lymphatics
- sensory nerve fibres
- accessory structure
what does plexus mean
a network of something
e.g network of blood vessels or nerves
what is the cutaneous plexus
a network of blood vessels that are present at the junction of the dermis/hypodermis
what does the cutaneous plexus do
supplies the hypodermis, deep dermis, the capillaries for the hair follicles and sweat glands
what is the subpapillary plexus
- it branches off the cutaneous plexus and lies deep to the papillary layer of the dermis
- is a network of blood vessels
what does the subpapillary plexus do
supplies oxygen and nutrients to the upper dermis and epidermis
describe what the hypodermis is
- is the subcutaneous layer
- dominated by adipocytes that produce subcutaneous fat
- the subcutaneous fat stores energy and provides insulation
- common layer for vaccinations to go
describe what a 1st degree burn is
- is superficial, only involves outer layer of epidermis
- has red/pink, dry look
- is painful
- usually no blisters
- remains a water and bacterial barrier
- heals 3-10 days
describe a normal 2nd degree burn
- involves epidermis + varying amounts of dermis
- is painful
- looks moist, red and blistered
- heals in approx 1-2 weeks with good dressings
describe a deeper 2nd degree burn
- involves epidermis + dermis
- may include a whiteish, waxy looking areas
- hair follicles and sweat glands may stay intact
- may have some loss of sensation and scarring
- heal time = 1 month
describe a 3rd degree burn
- is a full thickness burn ( goes through all layers till the subcutaneous tissue)
- may involve muscle and bone
- can vary in colour = waxy white to deep red or black
- has a hard, dry. leathery look
- no pain in the areas as sensory nerve endings = destroyed
- may require skin graft
- weeks to regenerate and scarring
