![Dab tsi pib ua qhov muaj peev xwm ua hauv plawv? Dab tsi pib ua qhov muaj peev xwm ua hauv plawv?](https://i.answers-medical.com/preview/medical-health/14121118-what-initiates-the-action-potential-in-the-heart-j.webp)
Video: Dab tsi pib ua qhov muaj peev xwm ua hauv plawv?
![Video: Dab tsi pib ua qhov muaj peev xwm ua hauv plawv? Video: Dab tsi pib ua qhov muaj peev xwm ua hauv plawv?](https://i.ytimg.com/vi/uHaxmEzI7lc/hqdefault.jpg)
2024 Tus sau: Michael Samuels | [email protected]. Kawg hloov kho: 2023-12-16 01:44
Cov cardiac action peev xwm originates los ntawm lub sinus node, nyob rau hauv lub siab txoj cai atrium (RA) (Fig. 7-1). Nws cov cell depolarize spontaneously thiab pib lub spontaneous depolarization ntawm muaj peev xwm nqis tes ua ntawm qhov tsis tu ncua los ntawm qhov ntswg qhov.
Xav txog qhov no, dab tsi yog qhov kev txiav txim siab ntawm lub siab?
Plawv peev xwm ua . Lub plawv peev xwm ua yog qhov hloov pauv me me ntawm qhov hluav taws xob (membrane peev xwm ) hla lub cell membrane ntawm plawv hlwb. Qhov no yog tshwm sim los ntawm kev txav ntawm cov atoms them (hu ua ions) ntawm sab hauv thiab sab nraud ntawm tes, los ntawm cov protein hu ua ion channels.
Ib yam li ntawd, 4 cov kauj ruam ntawm kev nqis tes ua yog dab tsi? Qhov muaj peev xwm ua tau yog tshwm sim los ntawm qhov pib lossis suprathreshold kev txhawb zog ntawm lub paj hlwb. Nws muaj plaub theem; hypopolarization, depolarization , overshoot, thiab repolarization . Ib qho kev txiav txim muaj peev xwm nthuav tawm raws lub cell membrane ntawm ib qho axon kom txog thaum nws mus txog lub davhlau ya nyob twg khawm.
Tsis tas li, dab tsi pib ua qhov peev xwm?
Tej yam peev xwm ua tau yog tshwm sim thaum sib txawv ions hla lub neuron membrane. Ib qho kev txhawb nqa ua ntej ua rau cov chaw sodium qhib. Vim tias muaj ntau ntau sodium ions nyob sab nraud, thiab sab hauv ntawm lub paj hlwb tsis zoo txheeb ze rau sab nraud, sodium ions maj mus rau hauv lub paj hlwb.
Dab tsi ua rau depolarization ntawm lub plawv?
Depolarization tshwm sim hauv plaub chav ntawm plawv : ob qho tib si atria ua ntej, thiab tom qab ntawd ob lub ventricles. SA node xa cov ntaub ntawv depolarization yoj mus rau atrioventricular (AV) node uas-nrog txog 100 ms ncua kom cia lub atria ua tiav kev cog lus-ces ua contraction hauv ob lub ventricles, pom hauv QRS nthwv dej.
Pom zoo:
Qhov twg ntawm cov hauv qab no yog qhov muaj peev xwm tshwm sim tshwm sim ntawm kev tswj hwm procainamide?
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Muaj ntau cov kev mob tshwm sim tom qab induction ntawm procainamide. Cov kev tsis zoo no yog ventricular dysrhythmia, bradycardia, hypotension thiab poob siab. Cov kev phom sij tshwm sim ntau dua yog tias cov koob tshuaj txhua hnub tau nce. Procainamide kuj tseem tuaj yeem ua rau kub cev tshuaj thiab lwm yam kev ua xua
Dab tsi ua rau kev txiav txim siab muaj peev xwm ua rau lub paj hlwb pib?
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Yog tias lub tshuab hluav taws xob muaj peev xwm nce mus txog qhov pib, kev ntaus nrig ntawm lub peev xwm (tseem hu ua kev xav ntawm lub paj hlwb) tau tshwm sim ntawm thawj qhov ntawm Ranvier ntawm lub paj hlwb. Zuag qhia tag nrho: Hauv cov kab mob nyob hauv cov hlab ntsha cov hlab ntsha tau pib los ntawm cov receptor hlwb
Yuav ua li cas lub plawv ua lub peev xwm nthuav tawm hauv plawv?
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SA Node tau txuas ncaj qha rau kev cog lus atrial cardiomyocytes thiab qee qhov kev coj ua uas paub zoo hu ua 'Interatrial Band' uas nthuav tawm qhov ua tau sai los ntawm sab xis mus rau sab laug atrium. Yog li, tom qab pib los ntawm SA Node, lub plawv ua haujlwm muaj peev xwm ua ntej kis mus thoob plaws ob qho tib si atria
Yuav tsum mus txog dab tsi thiaj li pib muaj peev xwm ua tau?
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Yuav tsum mus txog dab tsi thiaj li yuav pib muaj peev xwm ua tau (ua tau tshwj xeeb)? Kev txhawb siab yuav tsum mus txog qhov pib uas yog ntawm -55 mV 13. Cov peev txheej ua tau muaj tag nrho-lossis-tsis muaj txoj hauv kev. Txawm hais tias kev txhawb nqa pib los ntawm dendrite thiab taug kev los ntawm lub cev ntawm tes, qhov muaj peev xwm ua tsis tau pib txog thaum axon toj siab
Dab tsi yog qhov txawv ntawm qhov tseeb qhov pib thiab qhov sib txawv qhov pib?
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Qhov pib tsis txaus yog qhov tsawg kawg ntawm kev txhawb siab xav tau rau ib tus neeg kom pom qhov kev txhawb siab 50 feem pua ntawm lub sijhawm. Qhov sib txawv ntawm qhov sib txawv yog qhov sib txawv me tshaj hauv kev txhawb nqa uas tuaj yeem kuaj pom 50 feem pua ntawm lub sijhawm