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20 Cards in this Set
- Front
- Back
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Describe the stratum basalis
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1. Actively dividing stem cells along the basement membrane
2. Mitoses should be limited to this area |
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Describe the stratum spinosum
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Contains prominent desmosome attachments
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Describe the stratum granulosum
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Granular layer with keratohyaline granules
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Describe the stratum corneum
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1. Anucleate cells with keratin
2. Site for superficial dermatophyte infections |
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What is the site for superficial dermatophyte infections?
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Stratum corneum
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What later of the epidermis contains prominent desmosome attachments?
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Stratum spinosum
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Describe the papillary dermis
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Loose connective tissue beneath the epidermis
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Describe the reticular dermis
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Dense dermal collagen
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Where do melanocytes derive from?
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Neural crest cells
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Where are melanocytes located?
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Stratum basalis with dendritic processes extending between keratinocytes
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Where is melanin synthesized?
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In membrane-bound melanosomes
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Describe the synthesis of melanin
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1. Tyrosinase converts tyrosine to 3,4-dihydroxyphenylalanine (DOPA)
2. DOPA is converted to melanin 3. Melanosomes are transferred by dendritic processes to keratinocytes |
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What transfers melanosomes to keratinocytes?
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The dendritic processes of the melanocytes
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What is melanin synthesized from?
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Tyrosine
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Describe the distribution of melanocytes between races
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Number of melanocytes is essentially the same in all races
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Describe the differences in melanin degradation between races
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Melanin is degraded more rapidly in whites than in blacks
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Where are melanosomes in whites?
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Melanosomes are concentrates in the basal layer
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Where are melanosomes in blacks?
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Melanosomes are present throughout all layers
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Contrast melanosomes and melanocytes in whites and blacks
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1. In whites, melanosomes are concentrated in the basal layer
2. In blacks, melanosomes are present throughout all layers 3. Melanocytes are larger and have more dendritic processes in blacks than in whites |
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What stimulates melanin synthesis?
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Sunlight and adrenocorticotropic hormones
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