FunctionsThermoregulationWhen sweat evaporates it cools the body downExcretionOdor producingSynthesis of lipids reservesVitamin dImportant for calcium absorptionSensory infoNerve endings, light touch, and something elseImmune responseWhen things do make it across the barrierImmune recognition and rejectBreakdown of integumentaryCutaneous membrane (eneckurine?)Accessory membranes (adnexal structure)Integumentary system-cutaneous membrane over entire body and meets membranes of other systemsskin has 2 partsepidermis-stratified squamous epitheliumundergo keratinization- exclude all organelles and are dead cells when they are sheddermislayer of connective tissue under the epidermisthe closest blood vessels will get to epidermisepidermal junction is not flat but have folds into one anotherhelp keeps dermis and epidermis interlocked togetherblistering when separate because damagedepidermal ridgesdeepest part of epidermis that meets dermal papillaepidermisthin skin4 layerseverywhere else in the body and has hairsmissing the stratum lucidum (clear layer)thick skin5 layers only in certain areas (where brazions and areas for injury are highest)soles of feet and palms of handslayers (deepest to most superficial)stratum germinativum or stratum basale1 cell thick- only one!mitosis occurs hereproduces new keratinocytes- cells that will become keratinizedbasale cell tumors occur hereinstead of growing upwards they grow downwards into the dermis and considered malignant thenone daughter stays and the other continuresstratum spinosumcell junctions desmosome or macular adherencehave it to keep the cells together and not pull apartstratum granulosummore granulesstratum lucidumin thick skin and clearstratum corneummost superficialbasketweave like appearance (common in thin skin)very thin in thin skin and thick in thick skin BUT not how to determine must have stratum lucidumall dead heretakes 28 days to have a cell go from basale to corneumlonger to shed the cells but 28 days to go from basale corneumciryosis- takes a lot shortercellskeratinocytesall layers start in basaleundergo mitosisundergo keratinizationmelanocytesonly in basaleproduce melanin- pigment producingprotect from UVhave processesto move pigment to other cells surrounding itdendritic ?black people do not have more melanocytes everyone has the same amountthe amount of pigment produced and the ability to accept the pigment in the cells around them change skin colorsmerkel cellsonly in basalemechanoreceptors/neurotransmitterswhen skin deformed (contain neuro) to send signals to say (hey you are being deformed)have nerve plateslangerhansantigens presenting cellsin spinosumsend to preventive cells in the dermisconvulated nucleus (crenated)- looks like cut edge of a raisin)have tennis bracelet (beer brack granules)keratinizationribosomes produces tonofilaments accumulate as becomes superficialkeratohyalin granules meet tonofillaments and destroy the organelles in itfinish with keratin filled bags that use to be cellslamellar bodies- fuse with membrane and release oily substances that produces the water resistant barrier (through exocytosis)cant keep fluids in burn patients or organisms out of patients (become hypoglymic) because burned off lamellar bodiesskin colorblood supplypigments from foodsdegree and density of pigment granulesUV raysLook under melanocytesThick skinResistance to friction is neededWhere finger prints occur- deeper grovesDermisConnective tissue layer underneath epidermisPapillary layerSuperficialDermal papillaBlood vessels, lymphatic, sensory neuronsGives blood to epidermis through diffusion (papillary arterial plexus)Reticular layerDense Collagen and elastic fibersResists tensionLines of tension (cleavage lines or Langer’s Lines)Where surgeons make incisions to leave narrower scarsFree nerve ending- painPacinian corpuscle- in reticular layer- vibration or deep pressureLooks like a tree trunkMeissner corpuscle- dermal papillae- density compared to area (hands and feet skin of face are most common)Looks like the end of a q-tip run from side to sideBurn nomenclature1st- epidermis involvment2nd- papillary layer of dermis destroyed3rd- dee reticular layer destroyed4th- epidermis/dermis/ and partial damage to subcutaneous fat burned5th- epidermis/dermis/subcutaneous fat/ and underlying tissuesrule of ninescertain areas of body add up to 9 percent of skin on bodygreater than 50% of burns are unlikely to survivedegree of burns and percent of body can be helpful in determining the likelihood of survivaladnexal structurehair and hair follicleskeratinized filamentsbulb is deepestaretery and vein meet in hair bulb so greatest part of growtharrector pili muscle- smooth muscle that erects the hair attached to follicle and dermal/epidermal junctionsebaceous gland- makes hair greasysensory nerves at base of shaft4 typeslanugo- hair you are born withmatted darker disappersvellus- found on children until puberty very fineintermediate- found on the limbsterminal- found on adult skulls and facehair cycleproliferation (inactivity) and then involution2-5 year growth period (1/2 inch/month or 6 inch/year)anagen- growth- mosaic on which one is growing85 % of hairs2-5 yearscatagen phase- 1-2 week- down growing stagetelogen- follicle stays- resting phase10-15 % at a timecannot remake hair follicles once closed and bald stays closed and baldsebaceous glandsupper 1/3 hair folliclesecrete sebum onto hairholocrine manner of secretion (whole cell is secretion)active cells on outside and fill more and more with sebum as getting closer to duct (where miotic cells occur)sebaceous folliclesoccur on facenot associated with hair folliclesplugged produces acnesweat glands- KNOW DIFFERENCE WILL ASKmerocrine (eccrine)found everywhere (even axilla and groin)watery secretion without proteinperspirationthermoregulatorskick in late childhood and teenagersreticular dermisaprocrineonly in axilla and groin (armpits)high concentration of protein produces odorused to mark territory in animalslittle bit of cytoplasm is lostlarge lumen and large diameterin hypodermisnailshard keratinprotect tips of digits and limit mechanical distortionbody/bed/rootproduced in rootcuticleeponychium (top of nail)hyponychium (under free edge)lunula- unkeratinized in nail bed (or not completely kertanized)mammary glandsmodified aprocrine sweat glandglands then covered by skinareola darker circlenipple in center of areola (is that the way it has always been)men can get