MSK 03 - Skin Flashcards
what are the 6 functions of skin
temperature control
immune organ/immunilogical surveillance
sensory organ
protective barrier
vitamin D synthesis
fluid balance
what are the 3 key changes in the evolution of human skin
hairy to hairless
darker skin
eccrine sweat glands
how does UV damage the skin - hint: vitamin
damages the folate essential vitamin
what are the 3 layers of skin from outermost to innermost
epidermis
dermis
(bloodvessels)
subcutaneous fat
what are the 4 layers of the epidermis outermost to innermost
stratum corneum
stratum granulosum
stratum spinosum
stratum basale
what does the stratum granulosum contain and what is its role
keratohyalin granules which release filaggrin - a moisturizing factor
what holds the stratum spinosum together and what happens when it is oedematous
desmosomes
it is pulled apart when oedematous
where is the basement membrane located
below the stratum basale of the epidermis
at the dermo-epidermal junction
where are the melanocytes located in relation to the epidermis
under the stratum basale on the basement membrane
how is melanin produced by melanocytes - link to cell structure
melanocytes are dendritic cells which forms melanin/pigment
melanin is passed down the dendrites and delivered to keratinocytes
how does melanin help with UV protection
it forms a cap on the nucleus of the keratinocyte cells
the balance of what two pigments determines the colour of skin
eumelanin and phaeomelanin
what is kertain
protein forming skin, hair and nails
what is the purpose of the dermis - two things
structure and nutritional support
what are the 5 components of the dermis
mucopolysaccharides
elastin
collagen
cells
vessels
what are the 4 examples of cells in the dermis
macrophages
fibroblasts
dermal dendritic cells
mast cells
what are the 3 functions of the subcutaneous fat
insulation
biologically active - produces hormones
energy source
what are the 8 parts of the nail from most distal to proximal
nail plate
hyponychium
lateral nail fold
lunula
eponychium
cuticle
proximal nail fold
matrix
what is the lunula in the nail and why is it important
it is part of the matrix and part of the growing area of the nail
what is the hyponychium
where the finger ends
what is the matrix of the nail in terms of where it extends to
extends far beyond skin
what is the cuticle’s role in the nail
protects the nail
what is interesting about the matrix of the nail and cancer
it contains melanocytes so can develop melanoma here
what are the 7 parts of the hair follicle from most proximal to distal
hair shaft
pilosebasceous gland
arrector pilli muscle
bulge area
hair bulb
papilla
blood supply
what does the pilosebasceous gland do
forms grease/oil on skin
what is the papilla
where the hair grows from
what is the bulge area
source of stem cells and grows epidermis if all epidermis is lost
what nervous system controls the eccrine sweat glands and what is stimulates sweat generation
sympathetic nervous system
acetylcholine neurotransmitter
how does skin govern temp regulation - when it is hot and when it is cold
hot = sweat evaporation and alterations in cutaneous flow (vessels open up)
cold = shivering centrally mediated and alterations in cutaneous flow (vessels constricts so that blood goes to the central part of the body)
what is the function of goosebumps
hair rises as erector pilli muscle contracts which provides a thermal insulation layer when hairs go up
what is vitamin D important for
bone
what are the 4 types of touch that skin senses
pain
light touch
joint position sense
vibration
