Skin DSA Flashcards
skin fnxs
barrier tactile interaction body temp regulation sexual attractiveness immune system
skin immune fnx
cytokines and defensin production
Ag presentation via langerhans cells and dermal dendrocytes
layers of skin
epidermis
dermis (papillary and reticular)
subQ
adnexae
3 major structural units and specialized nn structures:
- pilar units
- eccrine units
- apocrine units
pilar units
hair units
pilosebaceous units and errector pili mm
eccrine units
eecrine glands and ducts
apocrine units
apocrine glands and ducts
layers of epi
stratum corneum stratum lucindum statum granulosum stratum spinosum stratum basalis
stratum corneum
corneocytes (final step in differentiation of keratinocytes differentiation)
thickest in palms and soles
stratum lucindum
only in palms and soles
stratum granulosum
keratinocytes lose their nuclei and cytoplasm appearing granular
stratum spinosum
keratinocytes become connected via desmosomes and produce lamellar bodies
langerhan cells are in this layer
basal/germinal layer
proliferating and non-proliferating keratinocytes attached to BM by hemidesmosomes
merkel cells here
apocrine glands
present deep in dermis
often at jnx of reticular dermis and subQ
melanocytes
each melanocyte will supplly about 30 keratinocytes with melanosomes
papillary dermis
finely woven type I collagen
some type III collagen and network of elastic fiber
healing by secondary intention
capillaries of superficial plexus
Basement membrane
defines invasion of carcinoma
contains proteins of blistering immune diseases
blistering immune diseases
bullous pemphigoid
dermatitis herpetiformis
epidermolysis bullosa
inflammatory conditions of BM
discoid lupus erythmatosus
lammellar/lamellated/pacinian corpuscle
encapsulated nn ending
pressure receptor
found in deep dermis or hypodermis
meissner/tactile corpuscles/papillae
touch receptor
confined to dermal papillae
most numerous in hand and feet
general skin nn supply
free nn endings detect pain and temp
innervation by sympathetic nervous system controls blood flow and hair movement
SubQ/hypodermis
loose and dense CT
adipocytes in lobules
large number of blood vessels (deep vascular plexus)
connects reticular dermis with fascia of underlying tissue
deep vascular plexus
sends perpendicular small aa to traverse the reticular dermis and supply blood to superficial vascular plexus in dermal papillae
subQ fnxs
body temp regulation
primary depot for fat storage
major skin layer where aging becomes apparent dt loss of adipose tissue
intrinsic aging changes
aberrant basal layer proliferation (increased risk of CA)
decrease in melanocytes: UV damage
decrease in langerhans cells
thinning: decrease in ground substance cells and adnexae, stiffer collagen and elastic fibers
decrease hair shaft diameter
by age 70 loose 25-50% of cross sectional diameter present in young people
solar elastosis
actininc degeneration of reticular dermis collagen
telangiectastias
sunburn
acute injury caused by mid-UV radiation
changes in dermis: increased blood flow, superficial vessels show endothelial swelling, perivenular edema, mixed perivascular inflammatory infiltrate
