Integumentary System

P&A Unit 6Integumentary SystemI. Integumentary System IntroA. Organ involved1. skin: largest organ of the bodyB. other parts involved: 1. sweat glands2. hair3. pores4. sebaceous (oil) glandsC. functions of the skin1. protective covering2. waterproof3. regulates body temp4. houses sensory receptors5. excretes small amount of waste: sweat

II. Skin & its tissues:A. skin has 3 layers:1. epidermis3. dermis3. subcutaneousB. skin (epithelial) tissue types** Not all are located in skin some on organs-- but always are exposed to a free surface1. reproduce quickly2. heal quickly3. connective tissue is always underneathC. Types of epithelial tissue1. simple squamousThin flat cellsLine lung air sacsLine capillaries/blood vessels2. simple cuboidalSingle layer/ cube shapedCovers ovaries/ kidney tubulesCovers glandsFunctions to secrete gland products3. simple columnarElonged single cellsLining of uterus and digestive tractSecretes digestive fluids and absorb nutrients4. Pseodostratified columnarAPPEAR layered, but are NOTUsually have cilia on endsLine passageways of respiratory system and reproductive systemSticky to trap things

5. stratified squamousMany layers of thick cells** forms outer layer of skin epidermisOld cells produce KeratinProduces dry, hardened outer coveringAlso lines mouth cavity6. Transitional epitheliumStretchableForms inner lining of urinary bladder

C. Epidermis1. composed of stratified squamous2. lacks blood vessels3. stratum basale- lowest layer of epidermis which is nourished by dermis blood vessels4. as stratum basale cells divide, older ones are pushed up5. older cells become KERATINIZED-proten, H2O proof coating6. dead cells accumulate on surface and form stratum corneum7. Function of stratum corneumProtection from:Water lossChemicalsMechanical injuryDisease agents8. contain MELANOCYTESDef: cells that produce melaninMelanin pigment which absorb sunlight protecting other cells9. Skin color** All humans have basically the same number of melanocytes -- it is the amount of pigment the cells produce that gives us our skin colorGenes determine how much pigment the melanocytes produceD. Dermis1. binds epidermis to underlying tissues2. composed of fibrous connective tissue- tissue has COLLAGEN & ELASTIN in itGives strength and elasticity3. many blood vessels to supply nutrients- aid in regulating body tempVasoconstricationVasodilation

4. Houses:Nerve fibersSensory receptorsHair folliclesSebaceous (oil) glandsSweat glandsE. Subcutaneous 1. lies beneath dermis2. mostly loose connective tissue and adipose (fat) tissue3. collagen & elastin fibers continue from dermis4. NO sharp boundary b/w dermis & subcutaneous5. adipose tissue = INSULATION6. contains MANY blood vesselsASSIGNMENTDUE THURSDAY APRIL 11. Inteview someone who has/had skin cancerTell their storyDiagnosisTreatmentWhat typeHow every effected them

OR2. Report on different types of skin cancerWhat distinguished themSeveritiesDetection

OR3. Prevention and treatment of skin cancer

2 pagesDouble spaced

DUE THURSDAY APRIL 1III. Accessory Organs of the skinA. hair follicles1. hair on all skin surface except:Palms, soles, lips, and external reproductive organs2. hair follicleDef: group of epidermal cells in a tubelike depression from which hair originatesROOT of hair is inside follicleRoot is only part of hair aliveThis is wear cell division takes place3. Older cells are pushed up and outward and become KERATINIZED = dead cellsProtein coat, hardenedWe dont feel pain when hair is cut, but do when hair is pulled4. arrector pili muscle is attached to each follicleIf muscle contracts = hair stands up = goose bumpsProduce heat to warm up body5. Hair color is determined by amount of melenin produced by melanocyte near follicle6. delayed-action geneCauses gray hair less melanin production7. LanugoHairy cloak of babies - mostly premies

B. Sebaceous glands1. group of special epithelial cells associated w/ hair follicles2. produce oily secretions = SEBUMMixture of adipose (oil) & dead cells3. Keeps hair and skin:SoftPliableWaterproof4. miliaSebaceous glands to not release sebum in uteroAfter birth, glands/pores may become cloggedLittle white bumps/pimplesC. Nails1. keratinized stratified squamous2. cells are forms in NAIL ROOTProximal end of nailLUNULA moon, is part of root3. nail lies in nail bedD. sweat glands1. occur all over skinMost numerous in palms and soles2. each gland has coil shaped proximal endContains sweat secreting epithelial cells3. Apocrine glandsSpecial sweat glands which respond to emotional stress and a person who is upset, frightened or in painMost numerous in groin, armpits associated with hair follicles3. Eccrine glandsNOT associated with hair folliclesRespond to increase in temperature and exerciseForehead, neck, back5. Sweat poresOpening in skin which a SWEAT DUCT leads to and sweats exitsSweat is H2O, urea, uric acidIV. Body Temp Regulations- cells produce heat constantly must get rid of heat constantly in order to maintain homeostasisA. When heat production is excessive:1. blood vessels dilate heat escapes2. NS stimulates Eccrine glands to become activeSweat = cooling effectB. If body is too cold:1. blood vessels constrict2. sweat glands become inactive3. muscles contract = shiver = heat production4. Arector Pili muscles contract = goose bumps5. heart beats slowerKeeps blood in vital organs/core longer = warmer6. breathe slowerKeeps air in lungs longer = warmerV. BurnsA. 1st degreeLeast severeMinor sunburnReddish skinTreat with topical ointmentB. 2nd degreeBlisters formFrom direct heat, severe sunburnTreat with ointmentDo not pop burn blistersC. 3rd degreeMost severeDeep into tissue even muscle tissueMany times need grafting of new skinBlackened skinNo pain directly at the site due to nerve damageVI. Rule of the NinesHandout