Pathology Flashcards
What stimulates Vitamin D?
Endocrine function of UV
What is the epidermis mainly made up of?
maturing squamous cells
Where are melanocytes found?
DEJ
What is the rate of melanocytes to basal cells?
1:10
What does the corneal layer consist of?
Keratinised cells
What is the granular layer rich in?
Keratohyalin granules
Where are the melanocytes found?
basal layer
What processes transfer pigment to keratinocytes?
Dendritic processes
What types of collagen make up the matrix?
Type 1 and 111
What else makes up the dermis?
Elastic fibres and ground substances (hyaluronic acid + chondroitin sulphate)
What the papilliary and reticular dermis?
Pap = thin, underneath epidermis
Ret = thicker bundles of type 1 collagen
Ret contains appendage structures (sweatglands anf puilosebaceous)
What is epidermis BM made of?
laminin and collagen IV
What is papillomatosis?
irregular epithelial thickening
What is spongiosis?
oedema in epidermis
Parakeratosis?
nuclei in keratin layers stay
Hyperkaratosis?
thickening of keratin layer
Acanthosis?
Increased epithelial thickening
Where does acne effect?
Sebaceous gland sites
What makes psoriasis occur?
turnover happening too quick and nuclei in the keratin layer
Where is sebum produced?
Sebaceuos glands
Keratin and sebum build up to create what?
blackheads
what is rosacea?
recurrent facial flushing
visible blood vessels
pustules
thickening of skin -rhinophyma
What can trigger Rosacea?
Sunlight. alcohol, spicy foods, stress
Whats the pathologyof rosacea?
pathcy inflam wih plasma cells
perifollicular granulomas
What do Immunobollous diseases have?
They have blisters as primary features.
Give 3 examples of Immunobollous diseases
Pemhigus
Bollous pemphigoid
Dermatitis herpetiformis
Describe Pemphigus
autoimmune disease where there is loss of integrity of epidermal cell adhesion
What antibody is related to Pemphigus vulgaris?
IgG made agaisnt desmoglein 3
Explain Pemphigus Vulgaris
immune complexes form on cell surface
disruption of desmosomes and activation of protease release.
results in Acantholysis
What also occurs in pemphigus vulgaris?
Lysis of intracellular adhesion sites
What antibody is related to Bullous pemphigoid?
IgG react with major/minor antigen of hemidesmosomes anchoring basal cells to basement membrane
what happens with older lesion of pemphigoid?
they show re-epithelialisation of their floor, mimicking PV
What GI disease has an association with Dermatitis herpetiformis?
Coeliac disease
What else is dermatitis herpetiformis associated with?
HLA-DQ2 haplotype
What is the hallmark sign if dermatitis herpetiformis?
papillary dermal microabscesses
What shows deposits of IgA in dermal papillae?
DIF
Where do Melanocytic lesions migrate to?
skin
uveal tract
leptomeninges
What is the MC1R gene?
It is a centrally placed gene which encodes MC1R protein which sits on the cell surface. It determines the pigment oft he skin
What does Eumelanin do?
hair colour other than red
What does Phaeomelanin do?
causes red hair
What does MC1R do?
converts phaeomelanin in eumelanin
What happens if a) 1 copy and b) 2 copies of the MC1R genes are defective?
a) causes freckles
b) red hair and freckles
What is an ephiles? (ephilides)?
a freckle (freckles)
What are Actinic lentigines?
liver spots
Explain Melanocytic naevi?
May be congenital or acquired, can be dysplastic, spitz, blue etc.
