Skin Pathology I Flashcards
skin function
protective covering - non-permeable tactile interaction body temp regulation sexual attraction immunity - APCs - langerhans epidermal dendritic cells
adnexa
pilar unit
eccrine unit
apocrine unit
two layers of dermis
papillary and reticular
layers of epidermis
stratum corneum stratum lucidum stratum granulosum stratum spinosum stratum basale
DEJ - dermal epidermal junction
papillary dermis
reticular dermis
horny layer
stratum corneum
apocrine glands
deep dermis at junction of reticular dermis and subQ tissue
more in inguinal, axilla, scalp
more eosinophilic cytoplasm
melanocytes
supplies pigment to squamous cells
desmosomes
intercellular bridges
-tight junctions
papillary dermis
finely woven type I collagen parallel to surface
healing second intention
capillaries of superficial plexus - blushing/sunburn
basement membrane
defines invasion of cancer
- proteins in blistering
- and other inflammatory conditions
superficial vascular plexus
in papillary dermis
rete pegs
interlock with dermal papillae
pacinian corpuscle
pressure receptor
encapsulated nerve endings
found in deep dermis or hypodermis
meissner corpuscles
touch receptor
- confined to dermal papillae
- hands and feet more numerous
skin nerve supply
free nerve endings - detect pain and temperature
sympathetic innervation - blood flow and hair movement
subQ tissue
hypodermis
adipocytes - lobules
fibroconnective tissue - septae
also - lots of blood vessels - deep plexus
connects reticular dermis with fascia of underlying tissue**
lobular paniculitis
pancreatitis
fat in subQ
septal paniculitis
erythema nododum
fibrous in subQ
function of hypodermis
1 - body temp regulation - vascular and adipose
2 - fat storage
3 - aging
skin wrinkling
loss of subQ adipose tissue in hypodermis
intrinsic aging
wrinkles
basal layer proliferation and risk of neoplasm
decrease in melanocytes - whitening
decreased langerhans cells
thinning
also decreased hair shaft diameter, decreased # of hair follicles, and redistribution of hair
actinic degeneration of reticular dermis collagen
solar elastosis
telangiectasias - dilated vessels close to surface also occurs
initial red with sunburn
vasodilation
sunburn changes
increased blood flow to dermis
superficial vessels - endothelial swelling
perivenular edema
perivascular inflammatory infiltrate
keratinocytes
squamous epithelial cells
elevated fluid filled lesion more than 5mm
bulla
linear traumatic epidermial disruption
excoriation
-deep scratch
thick rogh skin with prominent skin markings
lichenification
-repeated rubbing
flat circumscribed area 5mm or more that is colored
patch
flat circumscribed area less than 5mm that is colored
macule
separation of nail bed
onchyolysis
elevated dome shaped lesion <5mm
papule
elevated dome shaped lesion >5mm
nodule
elevated flat top lesion >5mm
plaque
discrete, pus-filled raised lesion
pustule
dry, horny, platelike excrescence
-result of imperfect cornification
scale
fluid filled raised lesion
bilster
fluid filled lesion >5mm
bulla
flui filled lesion >5mm
vesicle
itchy, transient, elevated lesion with variable blanching and erythema formed as result of dermal edema
wheal
loss of intercellular cohesion between keratinocytes
acantholysis
diffuse epidermal hyperplasia
acanthosis
abnormal, premature keratinization within cells below stratum granulosum
dyskeratosis
loss of epidermis
erosion
epidermal inflammatory cells
exocytosis
intracellular keratinocyte edema
hydropic swelling - ballooning
often with viral infections
Stratum granulosum hyperplasia, usually due to rubbing
hypergranulosis
Stratum corneum thickening, often with aberrant keratinization
hyperkeratosis
linear pattern of melanocyte proliferation within epidermal basal cell layer
lentiginous
surface elevation caused by hyperplasia and enlargement of contiguous dermal papilla
papillomatosis
keratinization with retained nuclei in stratum corneum
parakeratosis
normal in mucous membranes
intercellular edema of epidermis
spongiosis
discontinuity of skin showing complete loss of epidermis revealing dermis and subQ
ulceration
formation of vacuoles with or adjacent to cells
vacuolization
