Tus tshuab ntxuav dej sib npaug yog ib qhov khoom siv tshuab rau nyob nrog dej nyob ntawm tus cwj pwm tseem ceeb. Qhov no yog ib qhov tseem ceeb hauv lub tsev thíb, rau thaum sawv daws neeg thíb ua kev them nyiaj. Nws txwv kom cov ntaub ntawv thíb tuaj yeem tswj tau thaum tus cwj pwm zoo ib yam. Piv txwv li, thaum ib tug neeg thíb xav nrhiav kom paub seb ib hom chemical muaj kev sib raug li cas, tus cwj pwm tseem ceeb tuaj yeem tsim kev txwv tsam. ZONWON tsim tsoom VT2/VT4/VT6 Thov Tshuaj Ntuj Ci Zog kom txhawj tswv yim rau keeb kwm ntau dua thiab muaj qhov cuam tshuam ntau dua hauv lawv lub neej hais tswv yim. Cov dej no tsawg ntau thiab siv tau hauv ntau xwmfab nyob ntawm ntiaj teb.