Kev Ua Haujlwm ntawm Platelets hauv Kev Ntshav Clotting
Kev txhaws ntshav, lossis kev coagulation, yog ib qho txheej txheem tseem ceeb ntawm lub cev uas tiv thaiv kev los ntshav ntau dhau tom qab raug mob nqaij. Ntawm ntau yam cellular thiab molecular ua lub luag haujlwm tseem ceeb no yog platelets, tseem hu ua thrombocytes. Platelets yog cov me me, zoo li daim disk cell fragments uas tau los ntawm megakaryocytes hauv pob txha pob txha. Txawm hais tias lawv me me, cov cellular entities no ua lub luag haujlwm tseem ceeb hauv hemostasis - cov txheej txheem uas tiv thaiv kev los ntshav - thiab yog qhov tseem ceeb rau kev kho qhov txhab thiab kev noj qab haus huv ntawm lub plawv. Tsab xov xwm no delves rau hauv kev ua haujlwm nyuaj ntawm platelets hauv cov ntshav txhaws, piav qhia lawv txoj kev taug kev los ntawm kev ncig mus rau kev tsim cov ntshav txhaws ruaj khov.
Kev Tsim Platelet thiab Lub Neej Lub Neej
Txoj kev taug kev ntawm cov ntshav platelet pib hauv cov pob txha pob txha, qhov twg megakaryocytes dhau los ntawm cov txheej txheem nyuaj hu ua endomitosis, ua rau muaj ntau txhiab tus ntshav platelets ib megakaryocyte. Txhua lub ntshav platelet ntsuas li 2-3 micrometers hauv txoj kab uas hla thiab ncig hauv cov ntshav li ntawm 7-10 hnub ua ntej raug tshem tawm los ntawm lub po thiab lub siab.
Cov ntshav platelets muaj ntau yam organelles thiab granules, uas muaj cov clotting factors, enzymes, thiab growth factors. Lawv daim nyias nyias muaj ntau yam receptors uas ua rau lawv sib cuag nrog lwm cov cell thiab cov khoom hauv cov ntshav. Cov cwj pwm no ua rau cov ntshav platelets teb tau zoo thiab tseem ceeb rau kev raug mob ntawm cov hlab ntsha.
Lub Luag Haujlwm ntawm Platelets hauv Hemostasis
Kev ua kom cov ntshav tsis txhob khov yog ib qho txheej txheem uas muaj ntau kauj ruam uas muab faib ua thawj zaug ua kom cov ntshav tsis txhob khov (kev tsim cov ntshav txhaws) thiab theem ob ua kom cov ntshav tsis txhob khov (kev ua kom cov ntshav txhaws ruaj khov nrog cov fibrin mesh). Cov ntshav txhaws feem ntau koom nrog ob theem no.
1. Kev Tiv Thaiv Kab Mob Hlwb: Kev Tsim Cov Platelet Plug
Thaum cov hlab ntsha raug mob, cov hlwb endothelial uas ua kab rau cov hlab ntsha tso tawm cov cim qhia thiab ua rau cov collagen thiab cov ntaub so ntswg hauv qab endothelial tshwm sim. Qhov kev raug mob no ua haujlwm ua lub cim qhia kev ntxhov siab uas rub cov platelets uas ncig mus rau qhov chaw raug mob. Cov txheej txheem hemostatic tseem ceeb uas cuam tshuam nrog platelets suav nrog:
– Kev Sib Txuas: Kauj ruam thawj zaug yog kev sib txuas ntawm cov platelets rau ntawm cov matrix subendothelial uas raug nthuav tawm, feem ntau yog collagen. Qhov kev sib txuas no yog los ntawm von Willebrand factor (vWF), uas ua haujlwm ua tus choj ntawm cov platelet surface receptor glycoprotein Ib-IX-V complex thiab collagen.
– Kev Ua Kom Hlwb: Thaum cov ntshav sib txuas ua ke, cov ntshav platelets yuav ua kom hwb. Qhov kev ua kom hwb no ua rau muaj kev hloov pauv ntawm cov duab ntawm cov ntshav platelets los ntawm cov qauv zoo li disk mus rau cov duab ntse ntse, ua rau lawv thaj chaw ntau dua. Cov ntshav platelets uas ua kom hwb tso cov ntsiab lus ntawm lawv cov granules, uas suav nrog ADP, serotonin, calcium, thiab thromboxane A2. Cov tshuaj no ua rau cov ntshav platelets nyob ib puag ncig ua kom hwb thiab nrhiav cov ntshav platelets ntxiv rau qhov chaw.
– Kev Sib Sau Ua Ke: Cov platelets uas tau qhib lawm qhia txog glycoprotein IIb/IIIa receptor rau ntawm lawv qhov chaw, uas khi cov fibrinogen thiab vWF, tsim cov choj sib txuas ntawm cov platelet thiab ua rau cov platelet sib sau ua ke. Qhov kev sib sau ua ke no ua rau muaj ib qho tseem ceeb ntawm cov ntshav txhaws, ib ntus kaw qhov raug mob.
2. Kev Tiv Thaiv Kab Mob Thib Ob: Kev Txhawb Nqa ntawm Platelet Plug
Txawm hais tias qhov tseem ceeb ntawm cov ntshav txhaws sai sai, nws tsis muaj zog thiab xav tau kev txhawb nqa kom ntseeg tau tias cov ntshav txhaws ntev. Qhov thib ob ntawm cov ntshav txhaws cuam tshuam nrog cov txheej txheem coagulation, ib qho ntawm cov tshuaj tiv thaiv enzymatic uas ua rau muaj thrombin. Thrombin yog ib qho enzyme muaj zog uas hloov cov fibrinogen uas yaj tau mus rau hauv cov xov fibrin uas tsis yaj tau, uas sib xyaw los ntawm cov platelet plug, txhawb nqa nws. Cov fibrin mesh no ua rau cov ntshav txhaws ruaj khov thiab ua rau nws muaj zog tiv thaiv cov zog ntawm cov ntshav ntws.
Lub Luag Haujlwm ntawm Platelets Dhau Ntawm Hemostasis
Ntxiv rau lawv lub luag haujlwm tseem ceeb hauv hemostasis, platelets koom nrog ntau yam txheej txheem physiological thiab pathological:
– Kev Kho Mob Qhov Ncauj: Cov platelets tso tawm cov yam tseem ceeb uas ua rau cov hlwb loj hlob xws li cov platelet-derived growth factor (PDGF) thiab transforming growth factor-beta (TGF-β), uas yog qhov tseem ceeb rau kev kho thiab rov ua dua cov nqaij.
– Kev o: Cov platelets uas tau qhib lawm tso tawm cov cytokines thiab chemokines uas ua rau muaj kev o, ua rau muaj kev o. Lawv kuj sib cuam tshuam nrog cov leukocytes (cov qe ntshav dawb), ua rau lawv txoj kev tsiv mus rau qhov chaw o lossis raug mob.
– Kev Tiv Thaiv Kab Mob: Cov Platelets koom nrog kev tiv thaiv kab mob los ntawm kev paub txog cov kab mob ncaj qha los ntawm cov receptors toll-like (TLRs) thiab lwm cov receptors paub txog tus qauv. Lawv tuaj yeem ntes thiab nthuav tawm cov antigens rau cov hlwb tiv thaiv kab mob, yog li txuas cov kev tiv thaiv kab mob los ntawm kev tiv thaiv kab mob thiab kev hloov pauv.
– Kev Mob Thrombosis thiab Hemostasis Tsis Sib Npaug: Txawm hais tias cov platelets yog qhov tseem ceeb rau kev tiv thaiv kev los ntshav, lawv txoj kev tsis sib haum xeeb tuaj yeem ua rau muaj cov mob pathological. Kev ua haujlwm ntawm platelets thiab kev sib sau ua ke ntau dhau tuaj yeem ua rau muaj kev mob thrombosis, ua rau muaj cov mob xws li myocardial infarction, stroke, lossis deep vein thrombosis. Ntawm qhov tod tes, kev ua haujlwm ntawm platelets lossis kev tsim khoom tsis zoo ua rau muaj kev mob ntshav xws li thrombocytopenia.
xaus
Hauv paus ntsiab lus, cov ntshav platelets yog cov neeg tseem ceeb hauv cov txheej txheem ntshav txhaws. Txij li lawv txoj kev tsim nyob rau hauv pob txha pob txha mus rau lawv lub luag haujlwm tseem ceeb hauv kev hemostasis thawj zaug thiab thib ob, lawv yog cov neeg saib xyuas kev ruaj khov ntawm cov hlab ntsha. Lawv ua haujlwm sai thiab zoo rau kev raug mob ntawm cov hlab ntsha, tiv thaiv kev los ntshav thiab pib kho cov txheej txheem. Ntxiv mus, lawv cov haujlwm txuas ntxiv mus dhau qhov hemostasis, cuam tshuam rau kev kho qhov txhab, kev o, kev tiv thaiv kab mob, thiab ntau yam kab mob.
Kev nkag siab txog lub luag haujlwm nyuaj thiab ntau yam ntawm cov platelets tsis yog tsuas yog ua rau pom kev ntawm cov txheej txheem tseem ceeb ntawm lub cev xwb tab sis kuj tseem qhib txoj hauv kev rau cov kev kho mob tshiab. Cov kev kho mob uas tsom mus rau qhov ua haujlwm ntawm cov platelets tuaj yeem muab txoj hauv kev tshiab rau kev kho cov kab mob ntshav txhaws, cov kab mob plawv, thiab cov mob o. Thaum kev tshawb fawb txuas ntxiv mus nrhiav pom qhov nyuaj ntawm cov platelet biology, cov hlwb me me tab sis muaj zog no yuav nyob rau pem hauv ntej ntawm kev tshawb fawb kho mob.
