Qhov Tseem Ceeb - Paracellular vs Transcellular Diffusion
Kev thauj mus los ntawm cov khoom nyob rau hauv ib qho chaw nyob yuav tshwm sim raws li txoj kev sib txawv. Nyob rau hauv cov ntsiab lus ntawm diffusion, nws yog txhais raws li lub siab nyiam ntawm molecules txav tawm nrog lub hom phiaj ntawm kev ua tiav qhov chaw muaj. Hauv lwm lo lus, diffusion yog txav ntawm cov molecules los ntawm qhov chaw siab dua mus rau qhov chaw qis dua. Diffusion tuaj yeem ua haujlwm lossis tsis ua haujlwm. Nyob rau hauv passive diffusion, tsis muaj zog yog siv rau kev txav ntawm cov khoom, thaum nyob rau hauv active diffusion, lub zog yog siv. Thaum lub sij hawm kev thauj mus los ntawm molecules hla lub epithelial txheej ntawm plab, ob hom diffusion mechanisms tau piav qhia. Lawv yog paracellular diffusion thiab transcellular diffusion. Paracellular diffusion tshwm sim thoob plaws lub epithelium qhov twg cov tshuaj tau dhau los ntawm qhov chaw intercellular ntawm cov hlwb thaum nyob rau hauv transcellular diffusion, kev thauj mus los ntawm cov khoom tshwm sim los ntawm ob qho tib si apical thiab basolateral membrane. Qhov no yog qhov sib txawv tseem ceeb ntawm paracellular thiab transcellular diffusion.
Dab tsi yog Paracellular Diffusion?
Kev thauj mus los Paracellular yog kev txav ntawm cov tshuaj hla lub epithelium los ntawm qhov chaw nruab nrab ntawm lub hlwb. Qhov kev txav no yog hom passive diffusion. Yog li ntawd, tsis muaj kev xav tau ntawm lub zog raws li qhov diffusion tshwm sim los ntawm qhov concentration gradient. Nyob rau hauv paracellular diffusion, tus nqi nqus yog matched rau load. Qhov no tshwm sim vim hais tias ntawm lub mechanism ntawm diffusion tsis muaj ib qho kev thauj mus los uas muaj peev xwm yuav saturated. Paracellular diffusion muaj lub luag haujlwm me me hauv kev nqus cov as-ham hauv txoj hnyuv.
Daim duab 01: Paracellular Diffusion
Txawm li cas los xij, nws tau pom tias, kev ua haujlwm ntawm cov kab mob sib kis tau dhau los ua qhov tseem ceeb dua thaum muaj cov khoom noj muaj txiaj ntsig ntau hauv cov hnyuv lumen. Nyob rau hauv cov ntsiab lus ntawm kev nqus cov tshuaj nyob rau hauv lub plab zom mov, txoj kev paracellular plays lub luag haujlwm tseem ceeb. Hais txog hydrophilic pharmaceuticals, txoj hauv kev paracellular yog ib qho tseem ceeb vim nws pab txhawb kev txav ntawm cov tebchaw hla cov lipid membrane. Tsis tas li ntawd, cov tshuaj sib txuas uas tsis muaj kev sib raug zoo rau cov neeg thauj khoom hauv lub cell membrane yog thauj los ntawm paracellular diffusion. Kev thauj mus los Paracellular tsis muaj nyob thoob plaws cov ntshav-hlwb barrier. Yog li ntawd, lub capillaries ntawm cov ntshav-hlwb barrier tsuas muaj transcellular txoj kev.
Dab tsi yog Transcellular Diffusion?
Transcellular diffusion yog kev thauj cov molecules los ntawm ob qho tib si apical thiab basolateral membrane. Hauv lwm lo lus, transcellular diffusion yog txheej txheem ntawm kev txav ntawm cov kuab tshuaj los ntawm lub xov tooj ntawm tes los ntawm lub xov tooj ntawm tes. Qhov piv txwv tshaj plaws uas tuaj yeem muab rau transcellular diffusion yog kev thauj mus los ntawm cov piam thaj. Qhov no tshwm sim los ntawm lumen ntawm txoj hnyuv mus rau hauv cov kua dej extracellular los ntawm cov hlwb epithelial. Transcellular txav yog ib hom active diffusion. Yog li ntawd, hom diffusion no yuav tsum muaj zog.
Cov hlwb epithelial siv cov kev thauj mus los ntawm thawj thiab theem nrab uas lawv ua haujlwm tsis tu ncua nrog kev sib kis tsis zoo los ntawm ion raws. Qhov no ua rau lub transcellular thauj system hla cov ntaub so ntswg epithelial. Txoj kev transcellular yog suav tias yog ib qho tseem ceeb hauv cov ntsiab lus ntawm kev nqus cov as-ham hauv lub plab zom mov. Tag nrho txoj kev transcellular uas tshwm sim nyob rau hauv ib tug nyob system muaj peb subsets uas muaj xws li transcellular diffusion, transcytosis thiab active carrier-mediated tsheb thauj mus los. Transcellular diffusion tshwm sim los ntawm qhov concentration gradient uas pab txhawb kev thauj mus los ntawm cov kuab tshuaj los ntawm ib cheeb tsam ntawm siab concentration mus rau ib cheeb tsam ntawm tsawg concentration.
Dab tsi zoo sib xws ntawm Paracellular thiab Transcellular Diffusion?
- Ob leeg Paracellular thiab Transcellular Diffusion tshwm sim nyob rau hauv feem ntau ntawm cov capillaries ntawm lub cev.
- Ob leeg Paracellular thiab Transcellular Diffusion yog hom kev sib kis uas tshwm sim los ntawm thaj chaw siab dua mus rau thaj tsam qis dua.
Qhov txawv ntawm Paracellular thiab Transcellular Diffusion yog dab tsi?
Paracellular vs Transcellular Diffusion |
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| Kev thauj mus los Paracellular yog kev txav ntawm cov tshuaj hla lub epithelium los ntawm qhov chaw nruab nrab ntawm lub hlwb. | Transcellular diffusion yog kev thauj cov molecules los ntawm ob qho tib si apical thiab basolateral membrane. |
| Kev siv zog | |
| Kev siv hluav taws xob tsawg hauv paracellular diffusion. | Kev siv hluav taws xob ntau hauv kev sib kis ntawm tes. |
| Blood-Brain Barrier | |
| Kev thauj mus los Paracellular tsis tshwm sim los ntawm cov ntshav-hlwb. | Kev thauj mus los ntawm cov cell tuaj yeem tshwm sim los ntawm cov ntshav-hlwb. |
Summary – Paracellular vs Transcellular Diffusion
Diffusion yog txav ntawm cov molecules los ntawm qhov chaw siab dua mus rau qhov chaw qis dua. Kev thauj mus los Paracellular yog kev txav ntawm cov khoom hla lub epithelium los ntawm qhov chaw nruab nrab ntawm cov cell. Paracellular txav yog ib hom passive diffusion. Transcellular diffusion yog kev thauj cov molecules los ntawm ob qho tib si apical thiab basolateral membrane. Transcellular txav yog ib hom active diffusion. Yog li ntawd, hom diffusion no xav tau lub zog. Qhov no yog qhov txawv ntawm paracellular thiab transcellular diffusion.
