Patho NR 283 Exam 2 TEST PREP

Patho Exam 2 Integumentary system • SKIN- largest organ, 20% of body weight • ACCESSORIES 1. hair 3. Gland 2. nails • 1. PROTECTION 2. TEMPERATURE REGULATION 3. PROTECT AGAINST MICROOGRANISM 4. LOSS OF BODY FLUIDS 5. STRESS OF MECHANICAL FORCES 6. PRODUCTION OF VITAMIN D 7. IMMUNE SURVEILLENCE 8. PLEASUREABLE SENSATION • EPIDERMIS Layers 1. superficial outer layer 4. stratum spinosum 2. stratum corneum 5. stratum germinativum 3. stratum lucidum 6. Stratum basale • Keratinocytes- keratin • Melanocytes- melanin * Vitiligo- autoimmune related loss of melanocytes; depigmentation of patches of skin • Langerhan cells- present processed antigen to T- cells • Merkel cells- function as slowly adapting mechoreceptors • DERMIS 1. deeper layer, true skin 2. collagen, elastin, reticulum, and a gel-like ground substance 3. hair follicles, sebaceous glands, sweat glands, blood vessels, lymphatic vessels, nerves 4. Fibroblast- secrete collagen 5. mast cells- release histamine 6. macrophages- phagocytic immune cells * Histocytes- loose connective tissue; phagocytize pigments and debris of inflammation • SUBCUTANEOUS LAYER 1. fat cell or adipocytes and connective tissue 2. dermal collagen is continuous w/ the subcutaneous collagen 3. macrophages, fibroblast, fat cells, nerves, fine muscles, blood vessels, lymphatics, and hair root follicles • DERMAL APPENDAGES 1. hair, nails 2. Sebaceous glands- secrete sebum 3. Eccrine sweat glands- thermoregulate and cool the body through evaporation 4. Apocrine sweat glands – limited function • Blood supply and innervation 1. papillary capillaries provide a rich supply of blood 2. sympathetic nervous system regulates vasoconstriction and vasodilation through a- adrenergic receptors • PRIMARY LESIONS 1. Macule- flat, circumscribed area that a change in the color of skin (freckles, measles) 2. wheal- transient lesion w/ well defined and often changing borders caused by edema of the dermis ( insect bites, allergic reactions) 3. Papule- elevated, firm, and circumscribed area, measures less than 1 cm (warts) 4. Pustule- elevated, superficial lesion, filled with fluid ( acne, impetigo) • SECONDARY LESIONS 1. Excoriation- loss of epidermis, linear, hollowed, crusted (scabies, scratches) 2. Fissure- linear crack or break from the epidermis to the dermis, maybe moist and dry (athlete’s foot) 3. Erosion- loss of a part of the epidermis, depressed area, moist, glisten, rupture of a vesicle or bulla (chicken pox, diaper dermatitis) 4. Ulcer- loss of epidermis and dermis, concave, varies in size (pressure sore) 5. pressure ulcer- result of an unrelieved pressure on skin, causing underlying tissue damage * shearing forces, friction, moisture * occlude capillary blood flow w/ resulting ischemia and necrosis * STAGE 1 – nonblanchable erythema of intact skin * STAGE 2- partial thickness, skin loss, involves epidermis or dermis * STAGE 3- full thickness, skin loss, involving damage or subcutaneous tissue * STAGE 4- Full thickness, skin loss w/ damage to muscle, bone, or supporting structures • Decubitis ulcer- results when an individual lies or sits in one position for an extended period of time • Dermatitis or Eczema 1. most common 2. characterized by pruritus, lesions w/ distinct borders, epidermal changes 3. Chronic eczema