Lub npog ntsej muag pw npog lub stratum corneum ntawm daim tawv nqaij thiab muab dej noo rau nws. Nyob rau tib lub sijhawm, nws tseem muaj cov yeeb yaj kiab zoo-ua cov khoom ntiag tug. Ntawm lub hauv paus ntawm kev saib xyuas daim tawv nqaij yav hmo ntuj cov tshuaj pleev, me ntsis zaj duab xis-sib sau ua lus polymer sib txuas ntxiv, uas muaj qee yam zaj duab xis-GG quot; kaw" cov cuab yeej thiab tuaj yeem ua kom tawv nqaij ntws tawm hauv dej. Qhov no daim npog qhov ncauj yog ib daim ntawv qhia muab tshuaj noj kom zoo dua rau cov tawv nqaij kom nqus cov khoom xyaw zoo.
Lub hauv paus ntsiab lus ntawm lub ntsej muag pw: siv cov khaub ncaws tuab npog, thaiv qhov kev sib cuag ntawm lub ntsej muag lub ntsej muag thiab huab cua, thaiv qhov dej ntawm cov tawv nqaij kom ya raws, nce qhov av noo ntawm corneous txheej txheej rau nws; Qhov kub ntawm cov epidermis nce ntxiv kom thiaj li nthuav cov pores, uas yog qhov zoo rau kev nqus ntawm cov khoom noj khoom haus zoo.Tom qab ntawm qhov kub ntawm daim tawv nqaij nce, cov ntshav ncig tau nrawm, kom cov khoom noj ntxig nkag rau hauv daim tawv nqaij yuav kis mus tob thiab dav dua, thiab cov khoom noj muaj peev xwm rov ua dua sai sai.Qhov dej noo rau saum npoo ntawm cov tawv nqaij uas tsis tuaj yeem nqus tau yuav khaws cia hauv txheej txheej, thiab cov dej noo ntawm txheej txheej yuav puv, thiab daim tawv yuav zoo nkauj dua thiab nruj, thiab cov kab zoo yuav ua ntiav thiab lub teeb, thaum lub ntsej muag ci thiab ci ci. yuav ua tau zoo tuaj.