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14 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Epidermis |
Superficial región of the skin -Keratinized stratified squamous Epithelium |
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Epidermis 5 Distinct Layers |
1. Stratum basales 2. Stratum spinosum 3. Stratum gránulos un 4. Stratum lucidum (only in think skin) 5. Stratum corneum |
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Epidermis 4 Cell Types |
1. Keratinocytes 2. Melanocytes 3. Dendritic (langerhans) cells 4. Tactile (merkel) cells |
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Epidermis Main Structural Features |
*Stratum corneum: most superficial, 20-30 dead cells, flat membranous sacs w/ keratin, Glycolipids in extracellular space. *Stratum granulosum: 5 layers flattened cells, organelles deteriorating, cytoplasm full of lamellar granules- release lipids, keratohyaline granules *Stratum spinosum: several layers of keratinocytes unified by desmosomes, contain thick pretty keratin. *Stratum basale: deepest layer, 1 row active mitotic stem cells. |
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Epidermis Cells |
Keratinocytes: produce protein most cells of epidermis, connected by desmosomes. Melanocytes: 10-25% c3lls deepest epidermis, produce pigment of melanin, protect apical surface of keratinocytes nucleus from UV damage Dendritic (langerhans) cells: sensory touch receptors |
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Epidermis Layer (Basale) |
Stratum basale, basal layer: deepest layer, also called stratum germination, firmly attached to dermis, single row of stem cells, actively mitotic produces 2 daughter cells. 1 cell journey from basal to surface= takes 25-45 days it dies as moving toward surface. 1 cell remains in stratum basale as stem cell. Melanocytes compose 10-25% of this layer |
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Epidermis Layer (Spinosum) |
[prickly layer] Several layers thick Cell contain Web like system of intermediate pre-keratin filaments attached to desmosomes Abundant melanomas & dendritic cells |
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Epidermis Layer (Granulosum) |
Think 4 to 6 layers cell appearance: cells fatten, nuclei and organelles disintegrate Keratinization begins water resistant Glycolipids slows water loss cells above this layer die Too far from dermal capillaries |
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Epidermis Layer (Lucidum) |
[clear layer] (When asked 5 layers include lucidum! when asked for 4 DO NOT include!) Only in thick skin Think translucent band superficial to the stratum granulosum A few rows of flat dead keratinocytes |
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Epidermis Layer (Corneum) |
[horny layer] 20 to 30 rows of dead flat anucleate keratinized sacs 3 quarters of epidermal thickness Dead but cells have functions Protect deeper cells from others & water loss Barrier against biological chemical and physical assaults. |
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Dermis |
Strong, flexible connective tissue cells: fibroblasts, macrophages, sometimes mast/white/blood cells. Fibers in matrix bind body together - used to make leather - Contains, nerve fibers; blood and lymphatic vessels -Contain epidermal hair follicles oil / sweat glands - 2 layers: papillary/reticular |
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Dermis Layer (Papillary) |
Aerolar connective tissue w/ collagen / elastic fibers & blood vessels Loose tissue Phagocytescam patrol for microorganisms Dermal papillae: superficial peglike projections Meissner's corpuscles- touch receptors Nerve endings- pain receptors In think skin dermal ridges cause epidermal ridges - ridges called friction ridges - enhance group ability - sense of touch -fingerprint pattern |
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Dermis Layer (Reticular) |
80% dermal thickness Dense fibrous connective tissue Elastic fibers provide stretch recoil Collagen fibers: provide strength bind water cleavage lines: most collagen fibers parallel to skin surface externally invisible important to surgeons incisions parallel to cleavage to lines gap lessons heal readily |
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Dermatologist Skin Markings |
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