• ³laJJGck-and-³lue (³ruises): &&arks JJGcaused IIFby IIFblood esJJGcaping from vessels and JJGclotting IIFbeneath the skin.
·ppendages of the 451Skin ± ´air and ´air ¶olliJJGcles !2± ''$ails "3± ¸lands
´air • ±ead keratinized JJGcells of hard keratin • &&ore duraIIFble than soft keratin of skin • ''$ot found in palms, soles, lips, nipple or portions of external genitalia • ¶unJJGctions: – ±eteJJGct inseJJGcts IIFbefore they IIFbite or sting – ´air on sJJGcale proteJJGcts from physiJJGcal trauma, heat loss and sunlight – °yelashes shield the eyes – ''$ose hairs filter large partiJJGcles from the air we IIFbreath
¶urns 552Tissue damage infliJJGcted IIFby intense heat, eleJJGctriJJGcity, radiation or JJGchemiJJGcals resulting in denature JJGcell proteins, killing JJGcells in the affeJJGcted area. °valuating IIFburns: 340R673U!%&³ )*&° '($²'($³451S: divide the IIFbody into 11 areas eaJJGch aJJGcJJGcounting for 9% of the total IIFbody area 1 st degree = only epidermis is damaged 2 nd degree = epidermis and the upper region of the dermis, IIFblisters start to oJJGcJJGcur 3 rd degree = “full thiJJGckness” IIFburns, involving the entire thiJJGckness of the skin, nerve ends have IIFbeen destroyed, skin grafting is advised
441StruJJGcture of ´air ´airs “pili”: 451Shaft : keratinization is JJGcomplete, projeJJGcts from the skin. 340Root : keratinization is still ongoing, remainder of the hair deep within the folliJJGcle 552Three main JJGconJJGcentriJJGc layers of keratinized hair: &'edulla - JJGcentral JJGcore, soft keratin, aIIFbsent in fine hair ±ortex - IIFbulky layer, surrounds medulla, several layers of flattened JJGcells ±utiJKGcle - single layer of overlapping JJGcells, “roof shingles”, heavily keratinized, loss of this layer JJGcreates split ends.
451StruJKGcture of a ¸air °olliJKGcle ¸air folliJKGcles : fold down from the epidermal surfaJJGce into the dermis. ¸air IJFbulIJFb : deep end of the folliJJGcle, ~4mm IIFbelow skin surfaJJGce. ¸air 01-apilla : papillary IIFbump at the IIFbase of the hair IIFbulIIFb. 441Similar to the dermal papilla.
451StruJKGcture of a ¸air °olliJKGcle <<9Wall of hair folliJJGcle has 3 layers: 1. 00-eripheral JJGconneJJGctive tissue sheath ( 2. ¸lassy memIIFbrane 3. °pithelial root sheath (internal and external) ¸air matrix : loJJGcated a fraJJGction of a millimeter aIIFbout the hair IIFbulIIFb, FIORctively dividing FIreFI of the hair that produJJGces the hair. ·rreJKGctor pili musJKGcle : “raiser of hair”, IIFbundle of smooth musORcle ORcells
552Types of ´air !%&anugo : ²overing of fine soft hFIir seen on newNQborns and people with some disorders ( mFIlnutrition, FInorexiFI ) ;<8Vellus : ;;8Velvet, peFIORch fuzz , fine, light JJGcolored, and IIFbarely notiJJGced, oIIFbserved more in women FInd ORchildren. 562Terminal : ±arker pigmentation than vellus, thiORcker, ORcoFIrser, longer hFIir on sORcFIlp, eyeNQbrows FInd fFIORciFIl hFIir in men.
''$ails 441SJJGcale-like modifiORcFItion of the epidermis , forms JJGclear proteORctive ORcovering on fingers and toes ´eavily kerFItinized epidermFIl ORcells
'($ail 451StruJKGctures • ¶ree edge - no attaJJGchment to skin • ''$ail plate/IIFbody - visiIIFble attaJJGched portion • 00-roximal root - emIIFbedded in the skin • ''$ail IIFbed - deeper layers of the epidermis extended IIFbeneath the nail • ''$ail matrix responsiIIFble for nail growth • !%%unule - region that lies over the thiJJGck nail matrix, white JJGcresJJGcent • ²utiJJGcle (eponyJJGchium) - proximal nail fold projeJJGcts onto the nail IIFbody • ´yponyJJGchium - thiJJGckened region under the free edge of the nail.
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- Spring '18
- skin disorder