I- epidermis yincandelo elingaphandle kwesikhumba kwaye lenziwe ngamacandelo amahlanu. I-strneum corneum yilezo zingaphezulu kwezo zibalo ezintlanu kwaye ngokuyinhloko ziba ngumqobo.
Ngaphambi koo-1970, i-corneum yamacandelo yayicatshangelwa ukuba i-inert ye-biologically, njengephepha elincinci leplastiki elikhusela iindawo ezibonakalayo, ezincinci zesikhumba. Kwiminyaka embalwa edluleyo, izazinzulu ziye zafumanisa ukuba umsebenzi wezinto eziphilayo kunye neekhemikhali yenkqutyana ye-corneum empeleni iyinkimbinkimbi kwaye iyinkimbinkimbi.
Ukuqonda isakhiwo kunye nomsebenzi we-strneum corneum kubalulekile kuba kuyisitshixo sokuba unesikhumba esilungileyo kunye nesityebileyo. Le mizekeliso iza kukuthatha kwiindawo ezibalulekileyo ze-strneum corneum.
ICorneocyte
I-strneum corneum inesakhiwo sakhiwo "sitena kunye nomdaka", kwaye "izitena" kulo mzekeliso ziprotein zintsimbi ezibizwa ngokuba yi-corneocytes (jonga umzekeliso). I-corneocyte yenziwe ngamacu amancinci e-keratin kwi-matrix ehleliweyo. I-keratin inokubamba amaninzi amanzi phakathi kweefiber / iintambo. I-strneum corneum iqulethe malunga ne-12 ukuya kwe-16 yee-corneocytes, kwaye i-corneocyte nganye ine-thickness of 1 micrometer, ngokuxhomekeke kwezi zinto zilandelayo: ubudala, indawo ye-anatomical, kunye nokuvezwa kwemisebe ye-UV .
Lamellar Bodies
Imizimba ye-lamellar yenziwa kwi-keratinocytes ye- stratum spinosum kunye ne-stratum granulosum. Xa i-keratinocyte ikhula kwi-strneum corneum, i-enzymes ihlaziya imvulophu yangaphandle yamalungu e-lamellar, ikhulula iintlobo zeepids ezibizwa ngokuba ngamafutha e-free acids kunye nee-ceramide.
Intercellular Lipids
Ama-acid acetywayo kunye nee-ceramide ezikhishwa kwiimpawu ze-lamellar zidibanisa ndawonye kwi-strneum corneum ukuze zenze i-lipids. Ngenxa yokuba kukho iintlobo ezimbini zeepidids, olu luhlu lubhekiswa njengeli lamillar lipid bilayer. I-lipid bilayer idlala indima enkulu ekugcineni impahla ekhuselweyo yesikhumba kwaye iyafana "nomdaka" kwisitenxo sotena kunye nomdaka.
Envelope
I-corneocyte nganye ijikelezwe igobolondo yamaprotheni ebizwa ngokuba yi-envelope yeseli. Imvulophu yesilwane ibhalwe ngokuyinhloko kwiiprotheni ezimbini, i-loricrin ne-involucrin. Ezi proteins ziqulethe izixhumanisi ezinkulu phakathi komnye nomnye, okwenza ivulophu yefestile ibe yindawo engenayo i-corneocyte. Ezi zimbini zeentlobo zezivulo zeseli zichazwa ngokuthi "zinzima" kwaye "zibuthathaka," ngokusekelwe ekusebenzisaneni kwe-lamellar lipid bilayer kunye nevulophu yeseli.
Iimvulophu i-Lipids
Ukufakwe kwiimvulophu yeeseli ngumgca we-ceramide lipids oguqula amanzi. Ngenxa yokuba i-lamellar lipid bilayer iphinda iphephe amanzi, iamolekyuli zamanzi zibanjwe phakathi kwe-envelope lipids kunye ne-lipid bilayer. Oku kunceda ukugcina ukulinganisela kwamanzi kwi-strumum corneum ngokubamba iinqununu zamanzi, endaweni yokubavumela ukuba bangene kwiindawo eziphantsi ze-epidermis.
Corneodesmosomes
"Iingqungquthela" ezibamba i-corneocytes kunye nezakhiwo zeeprotheyini ezikhethekileyo ezibizwa ngokuthi i-corneodesmosomes. Ezi zakhiwo ziyinxalenye "yomdaka" kwisalathisi "sezitena kunye nomdaka". I-Corneodesmosomes yizona zakhiwo eziphambili ezimele zihlaziywe kwilusu ukuze zityhale kwinkqubo ebizwa ngokuthi i-desquamation.
I-Factory Moisturizing Factor (NMF)
I-NMF ye-Natural Factory factor (NMF) iqoqo le-compounds of water-soluble efumaneka kuphela kwi-strumum corneum. Ezi zixhobo ziquka malunga nama-20 ukuya kuma-30 ekhulwini kwomeko elomileyo le-corneocyte. Izixhobo ze-NMF zithatha amanzi ukusuka emoyeni kwaye zidibanise kunye nomxholo wazo wamanzi, ezivumela iingqimba zangaphandle ze-strneum corneum ukuba zihlale zi-hydrated ngaphandle kokuchazwa kwizinto. Ngenxa yokuba izixhobo ze-NMF zizinzulululwazi zamanzi, zithinteka kalula kwiiseli ezinxulumene namanzi-oko kutheni ukunxibelelana ngokuphindaphindiweyo ngamanzi ngokwenene kwenza ukuba isikhumba siphume. Umgca we-lipid ojikeleze i-corneocyte inceda ukunqanda i-corneocyte ukukhusela ukulahlekelwa kwe-NMF.
Inkqubo yokuHlanywa
Inkqubo yokuqhaqhaqha okanye ukuchithwa kwe-strneum corneum empeleni iyinkimbinkimbi kwaye inxalenye yale nkqubo iqondwa ngokupheleleyo. Kuyaziwa ukuba ama-enzyme amaninzi ahlaziya i-corneodesmosomes kwipatheni ethile, kodwa uhlobo oluchanekileyo lwama-enzyme okanye indlela aqaliswa ngayo ukuze kuqalwe inkqubo yokuqhaqhafaza. Amanzi kunye ne- pH badlala indima ebalulekileyo kwimisebenzi yee-enzymes.
> Imithombo:
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> Johnson, AW. (2015). I-Cosmeceuticals: Umsebenzi kunye neBlue Barrier. Iinkqubo kwiCermmetic Dermatology - Cosmeceuticals . Ed. Zoe Diana Draelos. Elsevier, 11-17.
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