Skin and Body MembranesWhat are body membranes?Epithelial MembranesEpithelial Membrane - CutaneousEpithelial Membrane - MucousEpithelial Membranes - SerousSlide 7Connective Tissue Membranes Synovial MembranesThe Integumentary System SkinFunctionsSlide 11Structure of the SkinEpidermisMelaninHerpes Simplex and the sun!DermisPapillary Layer of DermisReticular Layer of DermisSlide 19Decubitis UlcersSkin ColorCyanosisEmotions and Skin ColorAppendages of the SkinCutaneous GlandsCutaneous Glands Sebaceous GlandsImbalance of Sebaceous GlandsCutaneous Glands Sweat Glands – Sudoriferous GlandsSweat – Eccrine GlandProduct of Apocrine GlandHair and Hair Follicles HairHairSlide 33More HairHair FollicleSlide 36NailsHomeostatic Imbalances of SkinInfections and Allergies Athlete’s FootInfections and Allergies Boils and CarbunclesInfections and Allergies Cold SoresInfections and Allergies Contact DermatitisInfections and Allergies ImpetigoInfections and Allergies PsoriasisImportance of skinBurnsBurns - ClassificationWhen are burns critical?Skin CancerSlide 50Slide 51ABCD RuleThe EndSkin and Body MembranesChapter 4What are body membranes?•Cover surfaces, line cavities, protect organs•2 groups–Epithelial membranes – cutaneous, mucous, serous –Connective Tissue membranes – synovial membranesEpithelial Membranes•Coving and lining membranes•Do contain epithelial sheet, but all have connective tissue underneath•Simple organsEpithelial Membrane - Cutaneous•Skin•Superficial – keratinizing stratified squamous epithelium•Deep (dermis) – dense connective tissue•Exposed to air and dry membraneFigure 4.1aEpithelial Membrane - Mucous•Epithelium – varies per site, most often stratified squamous or simple columnar•Loose connective tissue – called lamina propria•Lines all body cavities open to exterior–What?–Respiratory, Digestive, Urinary, Reproductive•Wet membranes, bathed in secretions (or urine)•Adopted for absorption or secretion•Almost all produce mucus but urinary does notEpithelial Membranes - Serous•Superficial - Simple squamous •Deep – loose connective areolar•Line cavities closed to exterior (except dorsal body cavity and joint cavities)–What?Figure 4.1c–dEpithelial Membranes - Serous•Come in pairs –Parietal layer – lines wall of ventral body cavity, folds over on itself to form, always connected to wall–Visceral layer – covers outside layer of organ–Compare to balloon•Two layers separated by serous fluid – secreted by both layers, lay very close together–Why?•Name of serous membrane based on location–Peritoneum–Pleura–PericardiumConnective Tissue MembranesSynovial Membranes•Areolar connective tissue•Line fibrous capsules surrounding joints–Smooth surface–Secrete lubrication•Lines sacs of connective tissue of bursae and tendon sheathsFigure 4.2The Integumentary SystemSkin•Cutaneous Membrane•Include skin, sweat and oil glands, hair, and nails•Mostly protectiveFunctionsTable 4.1Functions•Upper layer contains keratin–Cornified (hardened) – protect from water loss•Rich capillary network and sweat glands–Controlled by nervous system–Regulate heat loss•Mini-excretory system –Urea, water, and salts lost•Manufac. Proteins imp. to immunity and Vit. D synthesis•Cutaneous Sensory Receptors in skin – touch, pressure, temperature, pain (part of nervous)Structure of the Skin•Epidermis – outermost layer–Stratified squamous able to keratinize•Dermis – underlying tissue–Dense connective tissue•Firmly connected, friction can separate–Blister – What happens?•Subcutaneous layer or hypodermis – adipose tissue–Not skin, anchors to organs–Shock absorber, insulator–Curves of womanEpidermis•Up to five layers thick–You get to learn them all in 2A!!•Avascular – shaving! •Most cells keratinocytes•Bottom layer stratum basale anchored to dermis by epidermal cells, receive nutrients via diffusion from dermis, millions of new cells daily, pushed outward (DEAD)•You will shed 40lb of skin in lifetimeFigure 4.3Melanin•Pigment – yellow to brown to black•Produced by melanocytes found in stratum basale•Exposed to sun, produce more melanin•Collected in melanosomes, taken up by keratinocytes•Act as umbrella protecting DNA•Freckles or moles are concentrated melaninHerpes Simplex and the sun!•Sun exposure damages skin–Depresses immune system–Develop cold sore more often after sun bathing•Overexposure of skin to UV rad. can lead to skin cancer–Black individuals seldom have skin cancer•Power of melaninDermis•Strong, stretchy envelop that holds you together•Hide – leather goods treated dermis•Dense Connective Tissue–Papillary layer – upper–Reticular layer - lower•Varies in thickness – feet/hands compared to eyelidsFigure 4.4Papillary Layer of Dermis•Uneven, projections called dermal papillae•Contain capillary loops which nourish epidermis•Some contain pain and touch receptors•Hands and feet – looped and whorl patterns for friction and grip•Determined genetically - fingerprintsFigure 4.4Reticular Layer of Dermis•Blood vessels, sweat and oil glands, deep pressure receptors•Phagocytes prevent bacteriaDermis•Collagen and elastic fibers •Collagen – toughness, attract and bind water, keep skin hydrated•Elastic – give skin elasticity•As age both decrease, subcutaneous looses fat, sag and wrinkle•Blood vessels to regulated heat–Hot – hot blood, radiate heat–Cold – bypass capillaries•Rich nerve supply – chapter 7Figure 4.5Decubitis Ulcers•Restriction of blood supply results in cell death, possibly skin ulcers•Bed sores – bedridden patients not turned, pressure points•Permanent damage results in ulcerationSkin Color•3 pigments contribute to skin color–Melanin – amount and kind in epidermis–Carotene – deposit in stratum corneum and subcutaneous tissue, orange-yellow pigment–Oxygen-rich hemoglobin – in dermal blood vessels–Think about variations!Cyanosis•Hemoglobin poorly oxygenated, blood and skin of Caucasians appear blue•Heart failure, breathing disorders•In black people, skin does not appear blue due to masking melanin – mucous membranes and nailshttp://meded.ucsd.edu/clinicalimg/upper_cyanosis.htmEmotions and Skin Color•Redness (erythema) – embarrassment, fever, hypertension, inflammation, or allergy•Pallor (blanching) – emotional stress (fear, anger),