Integumentary System

Integumentary SystemHealth Science 1Structure of the SkinSkin = Integument = Cutaneous Membrane 3 layersEpidermis Outermost coveringEpithelial cellsAvascular-no blood vesselsDermisTrue skin, inner layerConnective tissueVascularSubcutaneous

Epidermis StructureSTRATUM CORNEUM Outermost layerIn cells, cytoplasm replaced by KERATIN making them waterproof.Flat and scale-like cells that flake offFirst line of defense against surface bacteriaThickest on palms of hands, soles of feet

Epidermis StructureSTRATUM GERMINATIVUMInnermost or deepest epidermal layerReproductive layer cells form and push their way up, become keratinized, and replace the top layerContains MELANOCYTES cells that contain a pigment = MELANIN protects against rays and gives skin its color

Epidermis StructureMelaninBlack, brown, or has a yellow tint depending on racial originThe more melanin, the darker the skinCaucasians dont have much melanin in their melanocytesFreckles = patches of melaninAlbinism = no melaninSunlight stimulates melanocytes to make more melanin Tanning produced by UV rays.Prolonged exposure may lead to skin cancer!

Epidermis StructurePAPILLAERidges in stratum germinativum that arise from dermisCreate permanent ridges in fingers, palms and soles of feetThese friction ridges help with gripCause fingerprintsDermis StructuresThicker inner layer that contains:Connective tissueBlood vesselsNerve endingsMusclesHair folliclesOil and sweat glandsFat cellsDermis StructuresNerve Receptors in DermisSensory nerves heat, cold, touch, pain and pressure Touch receptors close to the surfacePressure receptors are deeper

Subcutaneous LayerSubcutaneous LayerLies under the dermis (not really part of integumentary system)Made up of loose connective tissueContains half of the bodys stored adipose tissue (fat)Also called hypodermis

Summarize!What are the structures of the skin?Appendages of the SkinHAIRAlmost everywhere on the bodyLength, thickness, type and color variesOuter layer = CORTEXInner layer = MEDULLAPart under the skin = ROOTPart outside the skin = SHAFTFOLLICLE = pocket in epidermis, hair insidePAPILLA = tuft of tissue in root, contains capillariesARRECTOR PILI MUSCLE = smooth muscle attached to follicle. How does this muscle cause goose bumps?Ans. When it is stimulated as by a chill, contracts causing the skin to pucker around the hair.

Appendages of the SkinNAILSNail is formed in the nail bed or MATRIXEpidermal cells fused together and fill with keratinSWEAT GLANDS (SUDORIFEROUS GLANDS)Perspiration is 99% waterDistributed over the entire skin surfaceLarge numbers under the arms, palms of hands, soles of feet and foreheadDuct extends to form a pore in the skin, perspiration excreted through the poresMay be activated by heat, pain, fever and nervousnessAverage fluid loss is 500 ml per day

Appendages of the SkinSEBACEOUS GLANDSSecret oil (SEBUM) that protects and lubricates the skinIntact skin = best protection against pathogens, toxins and water lossSkin generally too dry for microbial growth they do grow in moist areasMost skin bacteria associated with hair follicles or sweat glands Underarm perspiration odor caused by bacteria and perspiration

SUMMARIZE!What are the appendages of the skin?FYIThe best way to prevent the spread of disease is by hand washing.Functions of the Skin7 Functions:Protective coveringFirst line of defense against pathogens Regulates body temperatureBlood vessels constrict or dilate to regulate heat loss, perspiration also changes body temperatureManufactures Vitamin DSunlight causes the skin to make vitamin D which helps with healthy bone growth

Functions of the SkinSensory functionThe skin reacts to heat, cold, pressure and pain which can protect against injuryStorage of fat, glucose, water and saltsSkin stores water and lipids which helps store vitamins and mineralExcretionExcretes urea and excessive mineralsAbsorbs certain drugsTopical medications can be absorbed through the skinhttp://www.youtube.com/watch?v=BVIIgHyNRdIMaking skin and appendages

Disorders of the skinAcne vulgarisCommon and chronic disorder of sebaceous glandsSebum plugs pores area fills with leukocytesAlso blackheads, cysts, pimples and scarringAthlete's FootContagious fungal infectionUsually contracted in public baths and showersRx antifungal agents

Disorders of the skinDermatitisNon-specific inflammation of skinCan be rash reaction to soap, plants, etc.Can be emotional stress can cause skin blotchesEczemaAcute, chronic or noncontagious inflammation of the skinDry, red, itchy or scaly skinDisorders of the skinHerpes 1HSV 1 viral infectionCauses blister to form ex. cold sore or fever blisterCan spread through oral contactHerpes 2HSV 2 Blister in genital areaSpread through sexual contactPeriods of remission and exacerbationRx Acyclovir (antiviral drug that slows growth/spread)Can be passed to newborn during vaginal delivery

Disorders of the skinImpetigoAcute inflammation and contagious skin diseaseCause- staphylococcus or streptococcusVesicles that rupture and crustRx- antibacterial cream and antibioticsPsoriasisInflammation of skin Dry reddish patches with scalesElbow, knees, skin and scalpCause is unknownRx- moisturizers Disorders of the SkinRingwormFungal contagious infectionRaised, itchy circular patch with crustRx- griseofulvin- oral antifungal med.Scabieseasily spread skin disease caused by a very small species of miteRash, thin lines on skinRx- permethrin 5% creamDisorders of the SkinBURNSCaused by radiation, sun, boiling water, chemicals, fire or electricityRULE OF NINES Measures percent of body burned. Body divided into 11 area, each is 9% of body surface.

Rule of nines- BSA (body surface area)http://www.youtube.com/watch?v=6dUuvuqv9xUDisorders of the skinFIRST DEGREESuperficial Skin red and dryInvolves only epidermisRx cold waterHealing within one week

Disorders of the skinSECOND DEGREEEpidermis and dermis Pain, swelling, redness and blisteringSkin may be exposed to infectionRx pain medication, dry sterile dressingHealing within 2 weeks

Disorders of the skinTHIRD DEGREEEpidermis, dermis and subcutaneous layers Symptoms loss of skin, blackened skin May be life threatening

Disorders of the skinMALIGNANT MELANOMAOccurs in melanocytesMetastasizes to other areas quicklyAppears as brown or black irregular patch that occurs suddenlyA change in an existing wart or mole may indicate melanomaRx surgical removal of melanoma and surrounding area and chemotherapy

Disorders of the skinBasal cell carcinomaMost common skin cancer, least malignantRx- surgical removal, radiation or Squamous cell carcinomaArises from epidermisGrows and metastasizes quicklyRx- surgical removal or radiationPrognosis is good with early detection

Disorders of the skinMacule- flat area with different color ex. frecklesPapule- elevated solid are ex. elevated molePustule- pus filled area ex. acneUlcer- deep tissue loss ex. decubitus Vesicle- fluid filled raised area ex. chickenpox

Disorders of the integumentary systemSkin lesions:Compare these types of skin lesions.Macule

Papule

Pustule

3.06: Understand the functions and disorders of the integumentary system33

VesicleUlcerDisorders of the skinWarts small, usually painless growths on the skin caused by a virus called human papillomavirus (HPV)Lighter or darker in color, may be smoothRx- medication, cryotherapy, burning,