Pathology Flashcards
what is the epidermis mainly maid up of?
mainly maturing squamous cells
where is the mitotic pool located?
in the basal layer
where are melanocytes found?
at the DEJ
what is epidermis?
stratified keratinising squamous epithelium
what are prominent in prickle cells?
desmosomes
what is the granular layer rich in?
keratohyalin granules
what type of cells are present in the corneal layer?
differentiated keratinised cells
where are corneocytes shed from & what does this create?
shed from the surface of the epidermis to form house dust
what do melanocytes do?
synthesise melanin pigment
how is melanin pigment transferred to keratinocytes?
via dendritic processes
where are Langerhans cells found?
in upper & mid epidermis
what kind of cell are Langerhans cells?
dendritic
what do Langerhans cells do?
act as sentiniels monitoring environment for antigens
what’s the difference between black people’s melanocytes & white people’s?
black people’s melanocytes make more melanin
what is the dermis made up of?
matrix of type 1 & type 111 collagen
what is present in the dermis?
elastic fibres
ground substance
what is ground substance?
hyaluronic acid & chondroitin sulphate
describe papillary dermis & where it is found?
thin layer just beneath the epidermis
describe reticular dermis
thicker bundles of type 1 collagen
what does reticular dermis contain?
appendage structures e.g. sweat glands, pilosebaceous units
what is the epidermal BM made of?
laminin & collagen 4
can you see Langerhan’s cells using a normal stain?
no
what is hyperkeratosis?
increased thickness of keratin layer
what is parakeratosis?
persistence of nuclei in the keratin layer
what does parakeratosis indicate?
skin is turning over too quickly
what is acanthuses?
increased thickness of the epithelium
what is papillomatosis?
irregular epithelial thickening
what is spongiosis?
oedema fluid between squares appears to increase the prominence of intercellular prickles
what does severe spongiosis cause?
vesicles filled by oedema fluid
what are the 4 main inflammatory reaction patterns?
- spongiotic
- psoriasiform
- lichenoid
- vesiculobullous
describe what happens in the spongiotic inflammatory reaction pattern & give an example
intraepidermal oedema
e.g. eczema
describe what happens in the psoriasiform inflammatory reaction pattern & give an exampl
elongation of the rate ridges
e.g. psoriasis
describe what happens in the lichenoid inflammatory reaction pattern & give an exampl
basal layer damage
e.g. lichen planus & lupus
describe what happens in the vesiculobullous inflammatory reaction pattern & give an exampl
blistering
e.g. bullous pemphigoid, pemphigus & dermatitis herpetiforms
what happens in psoriasis?
pathogenesis remains elusive
- epidermal hyperplasia
- hereditary factors?
- new lesions at sites of trauma
- complement mediated attack on keratin layer
if you were to scrape a scale of a psoriasis plaque, what would happen?
pinprick bleeding
what are crumbly nails in psoriasis due to?
dystrophy due to increased turnover in their epithelial nail beds
what does the distribution of acne vulgarise reflect?
sebaceous gland sites
- face, upper back, anterior chest
what is released when acne spots burst?
sebum & keratin which is very irritating for the skin
what can you stain for in acne vulgaris?
androgen receptors
what does keratin plugging of pilosebaceous units cause?
distension 7 then infection of the unit
where is sebum produced?
by the sebaceous gland
what is an open comedone?
blackhead
what is a closed comedone?
whitehead
in which sex is rosacea more common?
females
what is rosacea?
recurrent facial flushing, visible blood vessels, pustules, thickening of skin
what is rhinophyma?
thickening of skin
namesake known triggers of rosacea
sunlight
alcohol
spicy foods
stress
which antibiotics does some rosacea respond to?
tetracyclines
what pathology is found in rosacea?
vascular ectasia pachy inflammation with plasma cells pustules perifollicular granulomas follicular demodex mites
where are demodex mites usually found?
in sebaceous duct
what happens around the mites?
lots of granulomatous inflammation
what is the primary feature of immunobullous disease?
blisters
what is pemphigus?
rare autoimmune bullous disease of variable severity
what causes pemphigus?
loss of integrity of epidermal cell adhesion
which drugs does pemphigus respond to?
steroids
how many distinct subtypes are there of pemphigus?
4, separable clinically & histologically