Alu hlinister tshuab, yog cov khoom siv ntim ntim tsuas yog siv rau encapsulate khoom hauv pob tshab yas blister. Hom ntim khoom no pab tiv thaiv cov khoom, nce nws pom, thiab yog li no txhawb kev muag khoom. Cov hlwv tuaj ntim tshuab feem ntau muaj cov khoom pub mis, cov ntaus ntawv sib zog, cov cuab yeej sib npaug thiab cov khoom tawm.
