Acid-base tshuav nyiaj li cas ua lub luag haujlwm loj hauv kev ua haujlwm ntawm tib neeg lub cev. Cov ntshav ncig hauv lub cev yog qhov sib xyaw ntawm cov cell muaj sia nyob hauv cov kua dej. Thawj qhov kev ruaj ntseg uas tswj cov qib pH hauv cov ntshav yog qhov tsis muaj qhov system. Qhov no yog lub cev lub cev ua haujlwm uas ua kom ntseeg tau tias qhov tsis sib xws ntawm cov kua qaub-puag tshuav yog tswj hwm los ntawm kev tiv thaiv pH tee. Nws yog dab tsi thiab nws muaj ntau yam, peb yuav pom hauv qab no.
Kev piav qhia
Lub kaw lus tsis yog qhov tshwj xeeb. Muaj ob peb ntawm lawv nyob rau hauv tib neeg lub cev, thiab lawv tag nrho cov muaj plasma thiab cov ntshav. Buffers yog cov hauv paus (proteins thiab inorganic compounds) uas khi lossis pub H + thiab OH-, rhuav tshem pH hloov hauv peb caug vib nas this. Lub peev xwm ntawm qhov tsis muaj peev xwm tswj tau qhov sib npaug ntawm cov kua qaub-puag yog nyob ntawm tus naj npawb ntawm cov khoom uas nws tau tsim.
hom ntshav buffers
Ntshav uas txav mus tas li yog cov hlwb nyob,uas muaj nyob hauv cov kua nruab nrab. Ib txwm pH yog 7, 37-7, 44. Kev khi ntawm ions tshwm sim nrog qee yam tsis muaj, kev faib tawm ntawm cov tshuab tsis yog hauv qab no. Nws tus kheej muaj cov ntshav plasma thiab cov qe ntshav thiab tuaj yeem yog phosphate, protein, bicarbonate lossis hemoglobin. Tag nrho cov tshuab no muaj ib qho yooj yim yooj yim mechanism ntawm kev txiav txim. Lawv cov haujlwm yog tsom rau kev tswj cov qib ions hauv cov ntshav.
Ntawm ntawm hemoglobin tsis
Lub hemoglobin tsis yog qhov muaj zog tshaj plaws ntawm txhua qhov, nws yog alkali nyob rau hauv cov hlab ntsha ntawm cov ntaub so ntswg thiab cov kua qaub hauv cov khoom nruab nrog cev xws li lub ntsws. Nws suav txog xya caum-tsib feem pua ntawm tag nrho cov peev txheej tsis muaj peev xwm. Cov txheej txheem no tau koom nrog ntau cov txheej txheem uas tshwm sim hauv tib neeg cov ntshav, thiab muaj globin hauv nws cov muaj pes tsawg leeg. Thaum cov hemoglobin tsis hloov pauv mus rau lwm daim ntawv (oxyhemoglobin), daim ntawv no hloov pauv, thiab cov kua qaub ntawm cov khoom nquag kuj hloov pauv.
Qhov zoo ntawm cov hemoglobin txo qis dua li cov carbonic acid, tab sis yuav zoo dua thaum nws yog oxidized. Thaum lub acidity ntawm pH tau txais, hemoglobin ua ke hydrogen ions, nws hloov tawm tias nws twb txo. Thaum cov pa roj carbon dioxide tshem tawm ntawm lub ntsws, pH ua alkaline. Nyob rau lub sijhawm no, hemoglobin, uas tau oxidized, ua raws li tus neeg pub khoom noj proton, nrog kev pab ntawm cov kua qaub-puag tshuav nyiaj li cas. Yog li, qhov tsis, uas muaj oxyhemoglobin thiab nws cov poov tshuaj ntsev, txhawb kev tso carbon dioxide tawm ntawm lub cev.
Qhov kev tsis sib haum no ua haujlwmlub luag haujlwm tseem ceeb hauv cov txheej txheem ua pa, vim nws ua haujlwm thauj cov pa oxygen mus rau cov ntaub so ntswg thiab cov kab mob hauv nruab nrog cev thiab tshem tawm carbon dioxide los ntawm lawv. Cov kua qaub-puag tshuav nyob rau hauv cov erythrocytes yog tswj nyob rau hauv ib tug tas li theem, yog li ntawd, nyob rau hauv cov ntshav ib yam nkaus.
Yog li, thaum cov ntshav saturated nrog oxygen, hemoglobin hloov mus rau hauv cov kua qaub uas muaj zog, thiab thaum nws tso pa oxygen, nws hloov mus ua cov organic acid tsis muaj zog. Cov kab ke ntawm oxyhemoglobin thiab hemoglobin yog kev sib hloov, lawv muaj nyob ua ib qho.
Ntawm ntawm bicarbonate buffer
Lub tshuab bicarbonate tsis muaj zog kuj tseem muaj zog, tab sis kuj tswj tau tshaj plaws hauv lub cev. Nws suav txog li kaum feem pua ntawm tag nrho cov peev txheej tsis muaj peev xwm. Nws muaj ntau yam khoom uas ua kom nws cov txiaj ntsig ob txoj hauv kev. Cov tsis muaj no muaj ib tug conjugated acid-base khub, uas muaj molecules xws li carbonic acid (proton source) thiab anion bicarbonate (proton txais).
Yog li, cov kab mob bicarbonate tsis txhawb nqa cov txheej txheem uas muaj cov kua qaub muaj zog nkag mus rau hauv cov hlab ntsha. Cov txheej txheem no khi cov kua qaub rau bicarbonate anions, tsim carbonic acid thiab nws cov ntsev. Thaum alkali nkag mus rau hauv cov ntshav, qhov tsis tuaj yeem khi rau carbonic acid, tsim cov ntsev bicarbonate. Txij li thaum muaj sodium bicarbonate nyob rau hauv tib neeg cov ntshav ntau dua carbonic acid, lub peev xwm tsis muaj peev xwm yuav muaj acidity siab. Hauv lwm lo lus, hydrocarbon bufferlub kaw lus (bicarbonate) zoo heev ntawm kev them nyiaj rau cov khoom uas ua rau cov ntshav acidity nce. Cov no suav nrog lactic acid, qhov concentration ntawm uas nce nrog kev tawm dag zog lub cev, thiab qhov tsis zoo no cuam tshuam sai heev rau kev hloov pauv hauv cov kua qaub-puag hauv cov ntshav.
Txheej txheem ntawm phosphate buffer
Tib neeg phosphate buffer system nyob ze li ob feem pua ntawm tag nrho cov tsis muaj peev xwm, uas cuam tshuam nrog cov ntsiab lus ntawm phosphates hauv cov ntshav. Cov txheej txheem no tswj cov pH hauv cov zis thiab cov kua dej uas nyob hauv cov hlwb. Cov tsis muaj phosphates inorganic: monobasic (ua raws li cov kua qaub) thiab dibasic (ua raws li alkali). Ntawm pH ib txwm, qhov sib piv ntawm cov kua qaub rau hauv paus yog 1: 4. Nrog rau qhov nce ntawm cov hydrogen ions, phosphate tsis system khi rau lawv, tsim cov kua qaub. Cov txheej txheem no yog acidic dua alkaline, yog li nws zoo kawg nkaus neutralizes acidic metabolites, xws li lactic acid, nkag mus rau tib neeg cov hlab ntsha.
Txhim kho cov protein buffer
Protein buffer tsis ua lub luag haujlwm tshwj xeeb hauv kev ruaj khov ntawm cov kua qaub-puag, piv rau lwm lub tshuab. Nws suav txog li xya feem pua ntawm tag nrho cov peev txheej tsis muaj peev xwm. Proteins yog tsim los ntawm cov molecules uas ua ke los tsim cov kua qaub-base compounds. Nyob rau hauv ib puag ncig acidic, lawv ua raws li alkalis uas khi cov kua qaub, nyob rau hauv ib qho chaw alkaline, txhua yam tshwm sim nyob ib ncig ntawm.
Qhov no ua rau muaj kev tsim cov protein tsis zoo, uasNws muaj txiaj ntsig zoo ntawm tus nqi pH ntawm 7.2 txog 7.4. Ib qho loj ntawm cov protein yog sawv cev los ntawm albumins thiab globulins. Txij li thaum tus nqi protein yog xoom, ntawm pH ib txwm nws yog nyob rau hauv daim ntawv ntawm alkali thiab ntsev. Qhov no tsis muaj peev xwm nyob ntawm seb muaj pes tsawg tus proteins, lawv cov qauv thiab cov dawb protons. Qhov tsis tuaj yeem cuam tshuam ob qho tib si acidic thiab alkaline khoom. Tab sis nws lub peev xwm yog acidic dua alkaline.
Ntseeg ntawm erythrocytes
Nquag, erythrocytes muaj pH tas li - 7, 25. Hydrocarbonate thiab phosphate buffers muaj qhov cuam tshuam ntawm no. Tab sis hais txog lub hwj chim, lawv txawv ntawm cov ntshav. Hauv erythrocytes, cov protein tsis ua lub luag haujlwm tshwj xeeb hauv kev muab cov kabmob thiab cov ntaub so ntswg nrog oxygen, nrog rau tshem tawm cov pa roj carbon dioxide ntawm lawv. Tsis tas li ntawd, nws tswj hwm tus nqi pH tas li hauv erythrocytes. Cov protein tsis nyob hauv erythrocytes muaj feem cuam tshuam nrog cov kab mob bicarbonate, txij li qhov piv ntawm cov kua qaub thiab ntsev ntawm no tsawg dua hauv cov ntshav.
Buffer piv txwv
Cov tshuaj muaj zog acids thiab alkalis, uas muaj cov tshuaj tiv thaiv tsis muaj zog, muaj pH sib txawv. Tab sis qhov sib xyaw ntawm acetic acid nrog nws cov ntsev khaws cov nqi ruaj khov. Txawm hais tias koj ntxiv cov kua qaub lossis alkali rau lawv, cov kua qaub-puag yuav tsis hloov. Ua piv txwv, xav txog acetate tsis, uas muaj cov kua qaub CH3COOH thiab nws cov ntsev CH3COO. Yog tias koj ntxiv cov kua qaub uas muaj zog, ces lub hauv paus ntsev yuav khi H + ions thiab tig mus rau hauv acetic acid. Ntsev anion txobalanced los ntawm kev nce hauv cov kua qaub molecules. Yog li ntawd, muaj kev hloov me ntsis hauv qhov piv ntawm cov kua qaub rau nws cov ntsev, yog li cov pH hloov pauv tsis txaus ntseeg.
Mechanism of action of buffer systems
Thaum cov khoom siv acidic lossis alkaline nkag mus rau hauv cov hlab ntsha, qhov tsis tuaj yeem tswj hwm tus nqi pH kom txog thaum cov khoom tuaj tawm los yog siv rau hauv cov txheej txheem metabolic. Muaj plaub buffers nyob rau hauv tib neeg cov ntshav, txhua tus muaj ob feem: ib tug acid thiab nws cov ntsev, raws li zoo raws li ib tug muaj zog alkali.
Cov nyhuv ntawm qhov tsis yog vim qhov tseeb tias nws khi thiab nruab nrab cov ions uas tuaj nrog cov muaj pes tsawg leeg sib haum rau nws. Txij li thaum nyob rau hauv lub cev feem ntau ntawm tag nrho cov ntsib nyob rau hauv-oxidized metabolic cov khoom, cov khoom ntawm cov tsis muaj anti-acid ntau tshaj li anti-alkaline.
Txhua qhov tsis muaj qhov system muaj nws tus kheej txoj cai ntawm kev ua haujlwm. Thaum pH qib qis dua 7.0, lawv cov haujlwm hnyav pib. Lawv pib khi ntau tshaj dawb hydrogen ions, tsim complexes uas txav oxygen. Nws, nyob rau hauv lem, txav mus rau lub digestive system, ntsws, daim tawv nqaij, ob lub raum, thiab hais txog. Xws li kev thauj mus los ntawm cov khoom siv acidic thiab alkaline ua rau lawv tshem tawm thiab tshem tawm.
Hauv tib neeg lub cev, tsuas yog plaub lub tshuab tsis siv neeg ua lub luag haujlwm tseem ceeb hauv kev tswj xyuas cov kua qaub-puag, tab sis muaj lwm yam buffers, xws li acetate buffer system, uas muaj cov kua qaub tsis muaj zog (tus pub) thiab nws cov ntsev (txais). Lub peev xwm ntawm cov txheej txheem notiv thaiv kev hloov pauv hauv pH thaum cov kua qaub lossis ntsev nkag mus rau hauv cov ntshav yog txwv. Lawv tuav cov kua qaub-puag tshuav tsuas yog thaum muaj cov kua qaub los yog alkali muaj zog hauv ib qho nyiaj. Yog tias nws dhau lawm, pH yuav hloov pauv sai heev, lub kaw lus tsis yuav tsum tsis ua haujlwm.
Buffers efficiency
Buffers ntawm cov ntshav thiab erythrocytes muaj qhov sib txawv. Nyob rau hauv tas li ntawd, nws yog siab dua, vim hais tias muaj ib tug hemoglobin tsis nyob ntawm no. Qhov txo qis ntawm cov ions tshwm sim nyob rau hauv cov kev taw qhia ntawm lub cell mus rau intercellular ib puag ncig, thiab ces mus rau cov ntshav. Qhov no qhia tau hais tias cov ntshav muaj qhov loj tshaj plaws tsis muaj peev xwm, thaum lub sij hawm intracellular ib puag ncig muaj qhov tsawg tshaj plaws.
Thaum cov hlwb metabolized, cov kua qaub tshwm sim uas nkag mus rau hauv cov kua dej sib txuas. Qhov no tshwm sim qhov yooj yim dua, qhov ntau ntawm lawv tshwm nyob rau hauv lub hlwb, txij li thaum ntau tshaj ntawm hydrogen ions tsub kom lub permeability ntawm lub cell membrane. Peb twb paub qhov kev faib tawm ntawm cov tshuab tsis siv neeg. Hauv erythrocytes, lawv muaj cov khoom siv tau zoo dua, txij li collagen fibers tseem ua lub luag haujlwm ntawm no, uas cuam tshuam los ntawm o ntawm cov kua qaub, lawv nqus nws thiab tso cov erythrocytes los ntawm hydrogen ions. Qhov peev xwm no yog vim nws cov cuab yeej nqus.
Kev sib cuam tshuam ntawm buffers hauv lub cev
Txhua cov txheej txheem uas nyob hauv lub cev yog sib cuam tshuam. Cov ntshav buffers muaj ntau lub tshuab, qhov kev koom tes ntawm kev tswj xyuas cov kua qaub-piv yog txawv. Thaum cov ntshav nkag mus rau hauv lub ntsws, nws tau txais oxygen.los ntawm kev khi rau hemoglobin hauv cov qe ntshav liab, tsim oxyhemoglobin (acid), uas tswj cov qib pH. Nrog kev pab ntawm carbonic anhydrase, muaj ib tug sib npaug purification ntawm cov ntshav ntawm lub ntsws los ntawm carbon dioxide, uas nyob rau hauv erythrocytes yog nthuav nyob rau hauv daim ntawv ntawm ib tug qaug zog dibasic carbonic acid thiab carbaminohemoglobin, thiab nyob rau hauv cov ntshav - carbon dioxide thiab dej.
Nrog rau qhov txo qis ntawm cov tsis muaj zog dibasic carbonic acid hauv erythrocytes, nws nkag los ntawm cov ntshav mus rau hauv erythrocyte, thiab cov ntshav yog ntxuav ntawm carbon dioxide. Yog li, tsis muaj zog dibasic carbonic acid tas li dhau los ntawm cov hlwb mus rau hauv cov ntshav, thiab cov tshuaj chloride anions tsis ua haujlwm nkag mus rau erythrocytes los ntawm cov ntshav kom tswj tau qhov nruab nrab. Yog li ntawd, cov qe ntshav liab yog acidic ntau dua li ntshav ntshav. Txhua lub tshuab tsis muaj kev ncaj ncees los ntawm qhov sib piv ntawm proton pub-acceptor ratio (4:20), uas yog txuam nrog cov peculiarities ntawm cov metabolism hauv tib neeg lub cev, uas tsim ib tug ntau ntawm acidic khoom tshaj alkaline sawv daws yuav. Qhov taw qhia ntawm cov kua qaub tsis muaj peev xwm tseem ceeb heev ntawm no.
Txau cov txheej txheem hauv cov ntaub so ntswg
Acid-base tshuav nyiaj li cas yog tswj hwm los ntawm buffers thiab metabolic hloov hauv cov ntaub so ntswg hauv lub cev. Qhov no yog pab los ntawm biochemical thiab physico-chemical txheej txheem. Lawv pab ua rau poob ntawm cov kua qaub-puag khoom ntawm cov khoom metabolic, lawv txoj kev khi, tsim cov tshuaj tshiab uas tau tawm sai sai ntawm lub cev. Piv txwv li, ib tug loj npaum li cas ntawm lactic acid yog tawm mus rau hauv glycogen, organic acids neutralized los ntawm sodium ntsev. Muaj zogCov kua qaub thiab alkalis yaj hauv lipids, thiab cov organic acids oxidize los ua carbonic acid.
Yog li, qhov tsis muaj qhov system yog thawj tus pabcuam hauv kev ua haujlwm ntawm cov kua qaub-puag hauv tib neeg lub cev. pH stability yog qhov tsim nyog rau kev ua haujlwm ntawm cov roj ntsha molecules thiab cov qauv, cov kabmob thiab cov ntaub so ntswg. Raws li ib txwm muaj, cov txheej txheem tsis muaj qhov sib npaug ntawm qhov kev taw qhia thiab tshem tawm cov hydrogen thiab carbon dioxide ions, uas pab tswj cov qib pH tsis tu ncua hauv cov ntshav.
Yog tias muaj qhov ua tsis tiav hauv kev ua haujlwm ntawm cov tshuab tsis zoo, tus neeg ntawd tsim cov kab mob xws li alkalosis lossis acidosis. Txhua lub tshuab tsis muaj kev sib cuam tshuam thiab tsom rau kev tswj xyuas qhov ruaj khov acid-puag tshuav nyiaj li cas. Tib neeg lub cev tsis tu ncua tsim cov khoom lag luam acidic ntau, uas yog sib npaug rau peb caug litres ntawm cov kua qaub uas muaj zog.
Kev tsis sib xws hauv lub cev yog muab los ntawm cov khoom muaj zog: phosphate, protein, hemoglobin thiab bicarbonate. Muaj lwm cov kab ke tsis sib xws, tab sis cov no yog qhov tseem ceeb thiab tsim nyog tshaj plaws rau lub cev muaj sia. Yog tsis muaj lawv pab, ib tug neeg yuav tsim ntau yam pathologies uas tuaj yeem ua rau coma lossis tuag.
