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WOCN program
| Term | Definition |
|---|---|
| Epidermis characteristics | Outermost layer of skin, avascular, turnover time usually 28 days |
| Layers of epidermis | Stratum corneum, lucidum, granulosum, spinosum, basale (aka germinativum) |
| Stratum Corneum structures | Dead keratinocytes, thin, stacked, anucleated, cells filled with keratin, stratum has lipid matrix, originate in the basal layer, have fully differentiated, shed daily |
| Stratum corneum function | Protection against aqueous, chemical, physical assault Thickness varies with age, gender and disease |
| Keratin | Tough fibrous insoluble protein that is primary component of skin, hair and nails |
| Stratum lucidum structure | 1-5 cells thick, has lysosomal enzymes, only found in thick skin areas- palms and soles of feet, is translucent |
| Stratum lucidum function | Degrades nucleus and organelles of keratinocytes |
| Stratum granulosum structure | flattened cells, contain keratohyalin granules, Odland bodies |
| Stratum granulosum function | has Odland bodies that produce lipids and enzymes, the mortar of the epidermis, provides barrier to water loss |
| Stratum spinosum structure | has keratinocytes, Langerhans cells |
| Stratum spinosum function | Provide adhesion between cells, provides resistance against mechanical forces, synthesize keratin filaments |
| Stratum basale structure | Aka germinativum, inner most layer, basal layer, next to basement membrane, active cells,, has rete's pegs, melanocytes, epidermal stem cells |
| Stratum basale function | is reproductive layer, proliferating keratinocytes, anchors the epidermis via Retes pegs cells start here and migrate upwards |
| Basement membrane zone structure | 2 zones- lamina lucida and lamina densa , has hemidesmosomes for adhesion fibronectin is the major protein |
| Basement membrane zone function | Anchors the epidermis to the dermis- this is the layer that is affected blister formation, full thickness wounds and third degree burns in wound healing the BMZ is disrupted and must be reformed |
| Dermis structure | 2 layers, papillary and reticular fibroblasts present, is vascular and innervated is 2-4mm thick ground substance present, contains collagen and elastin, glands and hair follicles |
| Dermis function | protection, connective tissue |
| Papillary dermis structure | just below Retes ridges, has pappliae that connect with Retes, capillary loops that supply O2 and nutrients via BMZ, lymph vessels present |
| Papillary dermis function | Supply O2 and nutrients to stratum basale |
| Reticular dermis structure | contains sebaceous glands, hair follicles, sweat glands,contains most of the connective tissue , has fibroblasts, mast cells, and macrophages |
| Reticular dermis function | supports the skin, has connective tissue and blood vessels gives skin it's strength and elasticity |
| Dermal proteins | Collagen and elastin |
| Collagen | Fibrous protein with high tensile strength |
| Elastin | Coiled fibers that allow for skin to return to shape |
| Hypodermis structure | Subcutaneous fat, |
| Hypodermis function | Attaches dermis to underlying structures, insulates, distributes pressure |
| Skin functions | barrier/protection, Vit D synthesis, thermoregulation, sensation, insulation, immunity |
| protective functions | Protection against pathogens, UVR, fluid loss, environmental irritants |
| Thermoregulation | Barrier between outside and internal environment to maintain body temp, circulation and sweating are mechanisms |
| explain Sensation | Nerve receptors perceive - pain, touch, temp, itch and pressure - also a protective mechanism - burning itching and tickling are basic sensations |
| Vit D synthesis | UVR converts a sterol to cholecalciferol, then is converted to calcitrol |
| Skin immune system | Langerhans cells, tissue macrophages, mast cells, AMPs (antimicrobial peptides) |
| Langerhans cells | Antigen presenting cells present to T cells |
| explain Tissue macrophages | Bacteriocidal, tumoricidal, antigen presenters, secrete growth factors, cytokines, atherogenisis, coagulation, wound healing and remodeling |
| Mast cells | Usually in reticular dermis, release histamines, chemotactic agents - involved in allergic responses, inflammatory diseases |
| acid mantle | inhibits pathogenic growth, 4-6.5 |
| Merkel cells | Sense light touch- are in rete pegs, near hair follicles, , are mechanreceptors- |
| Meissner corpuscles | Touch reception |
| Pacinian corpuscles | Pressure, coarse touch vibration and tension |
| What separates the 2 major layers of the skin | Basement membrane zone |
| How long does it take a cell to go from stratum basale to corneum | 14 - 28 days |
| Retes pegs | Epidermal protrusions of the basal layer that point downward into the dermis |
| Melanocytes | Approx. the same # in all skin types, in basal layer, melanin is in the dendritic process as melanosomes |
| Factors that alter skin characteristics | Age, hydration, sun, soaps, nutrition, medications, disease |
| How do Meds effect skin characteristics | Can alter skin flora, alter inflammatory response, cause dermatitis slow wound healing can cause photosensitivity photo toxicity . |
| skin ph ranges from ___ to ___ with a mean of ____ | 4,6.8, 5.5 |