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What is the Integumentary system?
- Represents hair, skin, nails
- Largest organ in body
- 3,000 square in in the average adult
- weighs about 6 lbs
- requires 1/3 of blood ejected from heart
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What are the functions of the integumentary system?
- Protective barrier from invaders and microorganisms
- insulation from extreme temp changes
- prevents dehydration in huge amounts
- eliminates waste via sweat
- Sensory receptors (touch, etc)
- Energy storage of fat for energy utilization
- Personal Identity
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What is the thickness of Skin
- (epidermis + dermis)
- 1.5 - 4.0 mm variations
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What is the Epidermis?
- Epidermis is the first and thinnest layer of the skin
- It's Thinner on scalp and eyelids, lips, and thicker on the palm of the hand or heel of the foot
- Superficially Cells are more dead and have more cell activity with depth
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What are the layers of the Epidermis? (From superficial to deep)
- Stratum Corneum
- Stratum Lucidum* not always present
- Stratum Granulosum
- Stratum Spinosum (part of stratum germinatum)
- Stratum Basale (part of stratum germinatum)
- --Basement Membrane-- separates Epidermis with Dermis
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What are the specialized cells and functions present in Epidermis?
- Malanocytes (pigmentation)
- Langerhans (immune respone in skin eg lesions, infx)
- Merkel cells (mechanoreceptor in basal layer to sense touch)
- Keratocytes (most in #, produce keratin ==> protection, barrier, impermeability)
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What is the Dermis and its layers?
- Dermis is the deeper layer of skin 2nd to Epidermis
- It is thicker than the Epidermis
- Papillary Layer
- Reticular Layer - (has appendages e.g. sebaceous glands, erector pilae, and hair follicles)
- Has Mast Cells for inflammatory response and maccrophages for immune response
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What is the Hypodermis?
- Deep to dermis (subcutaneous)
- Where superficial fascia is found for further support
- Isolates skin from the rest of the body
- where lots of FAT is found (adipose tissue)
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What are the 3 phases of Wound Healing?
- 1. Inflammatory
- 2. Proliferatibe (Fibroblastic phase)
- 3. Maturation/Remodelling phase
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What are the characteristics of the Inflammatory Phase?
- Normally Lasts ~ 3-7 days
- Vascular Changes (initial vasoconstriction to control bleeding, followed by vasodilation)
- release of prostoglandins (to attract WBC)
- WBC (neutrophils, macrophages) release growth factors for next phase of healing and engulf devitalized tissue
- release of platelets
- Release of Bradykinins and histamine (basophils) to increase capillary membrane permeability
- CARDINAL SIGNS: calor, dolor, tumor, rubor (heat, pain, swelling, redness)
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What are the characteristics of the Proliferative Phase?
- Can begin from Day 9 - 20 days
- Can overlap with the inflammatory phase
- 3 subphases:
- 1. Angiogenesis - reestablsh blood flow @ base of wound (dark redness)
- 2. Fibroplasia - laying down of gel matrix + new collagen at base of wound
- 3. Epithelialization - migration of epidermal scells across surface of wound inward (pink on wound edges, beefy red)
- Fibroblasts can convert to myofibroblasts pulling ends of tissue inward (Can't happen with out angiogenesis + fibroplasia, first)
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What are the characteristics of the Maturation/Remodelling Phase?
- Can begin from Day 3 - up to 2 years
- can also overlap
- Total wound resurfacing of wound
- new collagen matures and fibers shrink--> increased tension
- Light people: Starts out red but gets lighter
- Dark people: Starts out light but then starts to match surrounding
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What is Primary Intension Healing?
- Typically in surgical wounds
- Wounds that need epithelialization (only)
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What is Secondary Intension Healing?
- Usually pressure and concave wounds, Non surgical wounds
- Needs all 3 phases (Fibroplasia, Angiogenesis, and Epithelialization)
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What are the factors that prevent wounds from healing?
- 1. Infection (competition with critical colonization, 4 signs)
- 2. Continuous pressure
- 3. Trauma from dressing changes (ripping off bandages)
- 4. Use of cytotoxic agents (may kill granulation tissue)
- 5. Temperature extremes esp. hypothermia
- 6. Moisture (lack of)
- 7. Immunosupressed people (aids, diabetes, chemotherapy)
- 8. BMI, Low Protein
- 9. Dehydration
- 10. Poor perfusion to area (might need CABG, angioplasty)
- 11. Excess Adipose (obesity)
- 12. Predisposure (sensory deficits, increased risk)
- 13. O2 resp deficiencies (COPD)
- 14. Poor Mobility (immobile)
- 15. Medications (antiinflammatories, chemotherapy, immunosuppresive Rx's)
- 16. Poor habits (smoking, alcohol)
- 17. Incontinence (waste retiention)
- 18. Stress (emotional, psychological, cortisol dampens immunity)
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What are the clinical presentations of non-healing wounds?
- 1. calor, dolor, rubor, tumor --> chronic inflammatory respone
- 2. chronic proliferation (hypergranulation)
- 3. Hypogranulation
- 4. Hypertrophic scarring (Keloids, Dehiscense(suture line splitting open, Contractures)
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What are the considerations for proper wound healing?
- Control Infection
- Rid of necrotic tissue
- Minimize trauma
- Evaluate Meds
- Correct dressing
- Relieve pressiure
- Good Hydration and Nutrition
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