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17 Cards in this Set
- Front
- Back
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Epidermis and layers (superficial to deep)
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Derived from ectoderm; outermost layer of skin; barrier function; Stratum corneum, Stratum granulosum, stratum spinosum, and stratum basale
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Stratum Basale
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Deepest layer, attached to basement membrane; Contains keratinocyte stem cells
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Stratum Spinosum
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Composed of differentiating keratinocytes; in most parts of the body, makes up most of the epidermis; synthesize keratin
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Assembly steps of intermediate filaments
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Keratin, heterodimer, tetramer, protofilament intermediate filament
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Stratum granulosum
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Keratohyalin granules: filaggrin, involucrin, loricrin; Lamellar granules: ceramides, cholesterol, fatty acids, hydrolytic enzymes; important for the formation of the cornified envelope such as profilaggrin;
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Stratum Corneum
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Composes of corneocytes (lack nucleus and organelles and held together by corneodesmosomes); Primary barrier; variable thickness; No stratum corneum: mucosas, thinnest: face genitalia; Thickest; palms and soles
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Keratinization
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aka cornification; Process of keratinocyte migration and maturation; AVERAGE 28 days; stratum basale to stratum corneum 14 days, stranum corneum to shedding 14 days
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Pemphigus Vulgaris
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Acquired; Autoimmune bullous disease; Autoantibodies to desmosomal protiens; Desmoglein 1 and 3; Intraepidermal blistering; Flaccid easily ruptured bullae; oral and mucosal lesions; Nikolsky's sign positive; Tx with prednisone, azathioprine, mycophonolate mofetil, and rituximab
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Ichthyosis Vulgaris
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Autosomal dominant genetic condition; mutations in PROFILAGGRIN gene; defective filaggrin protein; 1:250 (fish scales); hyper linear palms; dry skin; associated with atopic dermatitis, allergic rhinitis, food allergies, and asthma; "fish scale"
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UVA rays
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Can extend into dermis; tanning and photoaging; 320 to 400 nm
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UVB rays
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Only make it to the epidermis and is responsible for burns 280-320
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Sun and UV radiation
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Main source of UV; highest levels from 10 to 4; high altitudes; can penetrate clouds water and glass
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Sunscreens that absorb UV light
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PABA, oxybenzone, avobenzone
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Sunscreens that reflect and scatter UV light
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titanium dioxide, and Zinc oxide
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SPF
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Minimal erythema dose (MED)=minumum amount of UVB that causes skin redness at 24 hours; only measures UVB protection; reapply sunscreen every 2 hours
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Keratins
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alpha helical proteins that make up intermediate filaments of the skin; divided into type I and type II keratins; results in a heterodimer; connect to desmosomes and hemidesmosomes
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Lamellar granules
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Not secreted until in the granule layer; important in forming the lipid barrier of the cornified layer; also contain hydrolytic enzymets that preomote desquammation
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