IiPlatelets (i-thrombocytes) ngamaqhekeza amancinci e-cytoplasm akhutshwe kwi-cytoplasm ye-Megakaryocyte ekhulile kumongo wethambo.Nangona i-Megakaryocyte lelona nani lincinci leeseli ze-hematopoietic kumongo wethambo, libalelwa kwi-0.05% yenani lilonke leeseli ezinomongo wethambo, iiplatelet ezizivelisayo zibaluleke kakhulu kumsebenzi we-hemostatic womzimba.IMegakaryocyte nganye inokuvelisa iiplatelet ezingama-200-700.
Isibalo seplatelet yomntu omdala oqhelekileyo (150-350) × 109/L.Iiplatelets zinomsebenzi wokugcina ingqibelelo yeendonga zemithambo yegazi.Xa i-platelet count iyancipha ukuya kuma-50 × Xa uxinzelelo lwegazi lungaphantsi kwe-109 / L, ukwenzakala okuncinci okanye ukunyuka kwengcinezelo yegazi kunokubangela amabala e-stasis yegazi esikhumbeni kunye ne-submucosa, kunye ne-purpura enkulu.Oku kungenxa yokuba iiplatelet ziyakwazi ukuhlala eludongeni lwe-vascular nanini na ukuzalisa izikhewu ezishiywe yi-endothelial cell detachment, kwaye zinokudibanisa kwiiseli ze-vascular endothelial, ezinokudlala indima ebalulekileyo ekugcineni ingqibelelo yeeseli ze-endothelial okanye ukulungisa iiseli ze-endothelial.Xa iiplatelet zimbalwa kakhulu, le misebenzi inzima ukuyigqiba kwaye kukho umkhwa wokopha.Iiplatelet kwigazi elijikelezayo ngokuqhelekileyo zikwimeko "emileyo".Kodwa xa imithambo yegazi yonakalisiwe, iiplatelet zisebenza ngokudibana komphezulu kunye nesenzo sezinto ezithile zokudibanisa.Iiplatelet ezisebenzayo zinokukhulula uthotho lwezinto eziyimfuneko kwinkqubo ye-hemostatic kunye nokwenza imisebenzi ye-physiological efana nokunamathela, ukuhlanganiswa, ukukhululwa, kunye ne-adsorption.
Iiplatelet ezivelisa iMegakaryocyte nazo ziphuma kwiiseli ze-hematopoietic stem kumongo wethambo.Iiseli ze-Hematopoietic stem kuqala zahlula kwiiseli ze-megakaryocyte progenitor, ezaziwa ngokuba yikholoni eyenza iyunithi ye-megakaryocyte (CFU Meg).Iichromosomes kwinucleus yeprogenitor cell stage are 2-3 ploidy.Xa iiseli ze-progenitor ziyi-diploid okanye i-tetraploid, iiseli zinamandla okwandisa, ngoko ke le yinqanaba apho imigca yeMegakaryocyte yandisa inani leeseli.Xa iiseli ze-megakaryocyte ze-progenitor zahlula ngakumbi kwi-8-32 ye-ploidy Megakaryocyte, i-cytoplasm yaqala ukwahlula kwaye inkqubo ye-Endomembrane yagqitywa ngokuthe ngcembe.Ekugqibeleni, i-membrane ye-membrane yahlula i-cytoplasm ye-Megakaryocyte kwiindawo ezininzi ezincinci.Xa iseli nganye yahlulwe ngokupheleleyo, iba yiplatelet.Nganye, iiplatelets ziyawa kwiMegakaryocyte ngesithuba esiphakathi kweeseli ze-endothelial zodonga lwe-sinus lwe-vein kwaye zingene kumlambo wegazi.
Ukuba neempawu ezahlukeneyo ngokupheleleyo ze-immunological.I-TPO yi-glycoprotein eveliswa ikakhulu yizintso, kunye nobunzima be-molecular malunga ne-80000-90000.Xa iiplatelet egazini ziyancipha, ukuxinwa kwe-TPO egazini kwandisa.Imisebenzi yalo mba wolawulo ibandakanya: ① ukuqinisa iDNA synthesis kwiiseli zabazali nokwandisa inani leepolyploids zeseli;② Ukuvuselela iMegakaryocyte ukwenza iprotheni;③ Yandisa inani elipheleleyo leMegakaryocyte, okukhokelela ekwandeni kwemveliso yeplatelet.Okwangoku, kukholelwa ukuba ukwanda kunye nokwahlula kweMegakaryocyte kulawulwa ikakhulu yizinto ezimbini ezilawulayo kwizigaba ezimbini zokwahlula.Aba balawuli babini yi-megakaryocyte Colony-stimulating factor (Meg CSF) kunye ne-Thrombopoietin (TPO).I-Meg CSF yinto elawulayo eyenza ngokukodwa kwisigaba se-progenitor cell, kwaye indima yayo kukulawula ukwanda kweeseli ze-megakaryocyte progenitor.Xa inani elipheleleyo leMegakaryocyte kwithambo lethambo liyancipha, ukuveliswa kwalo mbandela wokulawula ukwanda.
Emva kokuba iiplatelet zingene egazini, zinemisebenzi ye-physiological kuphela kwiintsuku ezimbini zokuqala, kodwa ubomi babo obuqhelekileyo bunokuba yi-7-14 iintsuku.Kwimisebenzi ye-physiological hemostatic, iiplatelet ngokwazo ziya kuhlukana kwaye zikhulule zonke izinto ezisebenzayo emva kokuhlanganiswa;Inokuthi idibanise kwiiseli ze-vascular endothelial.Ukongeza kokuguga kunye nokutshatyalaliswa, iiplatelets zinokuthi zisetyenziswe ngexesha lemisebenzi yazo yomzimba.Iiplatelet ezigugayo zigqunywe kwi-spleen, isibindi kunye nezicubu zemiphunga.
1. I-Ultrastructure yeeplatelet
Ngaphantsi kweemeko eziqhelekileyo, iiplatelet zivela njengeediski ze-convex ezincinci kumacala omabini, kunye nobubanzi obuphakathi kwe-2-3 μ m.Umthamo ophakathi ngu-8 μ M3.IiPlatelets ziiseli ze-nucleated ezingenalo isakhiwo esithile phantsi kwe-microscope ebonakalayo, kodwa i-ultrastructure eyinkimbinkimbi inokubonwa phantsi kwe-electron microscope.Okwangoku, ukwakheka kweeplatelet ngokuqhelekileyo kwahlulwe kwindawo ejikelezileyo, indawo ye-sol gel, indawo ye-Organelle kunye nendawo ekhethekileyo yenkqubo ye-membrane.
Umphezulu weplatelet oqhelekileyo ugudileyo, kunye nezakhiwo ezincinci ze-concave ezibonakalayo, kwaye yinkqubo evulekileyo ye-canalicular (OCS).Ummandla ojikelezayo weplatelet surface iqulethwe ngamacandelo amathathu: umaleko wangaphandle, i-unit membrane, kunye ne-submembrane area.Ingubo ikakhulu iqulunqwe ngee-glycoproteins (GP), ezifana ne-GP Ia, i-GP Ib, i-GP IIa, i-GP IIb, i-GP IIIa, i-GP IV, i-GP V, i-GP IX, njl. ukuya kwi-TSP, i-thrombin, i-collagen, i-fibrinogen, njl njl. Kubalulekile ukuba iiplatelet zithathe inxaxheba kwi-coagulation kunye nokulawulwa komzimba.I-membrane yeyunithi, eyaziwa ngokuba yi-membrane ye-plasma, iqulethe i-protein particles efakwe kwi-lipid bilayer.Inani kunye nokusabalalisa kwezi ngqungquthela zihambelana nokunamathela kweplatelet kunye nomsebenzi wokudibanisa.I-membrane iqulethe i-Na + - K + - ATPase, egcina ukuhlukana kwe-ion yoxinaniso ngaphakathi nangaphandle kwe-membrane.I-submembrane zone ibekwe phakathi kwendawo engezantsi ye-membrane yeyunithi kunye necala langaphandle le-microtubule.Indawo engaphantsi kwe-submembrane iqulethe i-submembrane filaments kunye ne-Actin, ehambelana nokunamathela kweplatelet kunye nokudibanisa.
I-Microtubules, i-microfilaments kunye ne-submembrane filaments zikhona kwindawo ye-sol gel yeeplatelet.Ezi zinto zenza i-skeleton kunye ne-contraction system ye-platelet, idlala indima ebalulekileyo kwi-platelet deformation, ukukhutshwa kwamasuntswana, ukuzolula, kunye ne-clot contraction.I-Microtubules yenziwe yi-Tubulin, i-akhawunti ye-3% yeprotheni epheleleyo yeplatelet.Umsebenzi wabo oyintloko kukugcina imilo yeeplatelet.I-Microfilaments iqulethe i-Actin, eyona nto ininzi iprotheni kwiiplatelet kunye ne-akhawunti ye-15% ~ 20% yeprotheni epheleleyo yeplatelet.Imicu ye-Submembrane zizinto zefiber, ezinokunceda i-Actin-binding protein kunye ne-Actin crosslink zibe zizithungu kunye.Kwisiseko sobukho beCa2 +, i-actin isebenzisana neprothrombin, i-contractin, iprotheni ebophelelayo, i-co actin, i-myosin, njl.
Itheyibhile ye-1 yePlatelet eyiNtloko yeMembrane Glycoproteins
Indawo ye-Organelle yindawo apho kukho iintlobo ezininzi ze-Organelle kwiiplatelets, ezinempembelelo ebalulekileyo kumsebenzi weeplatelet.Ikwayindawo yophando kumayeza anamhlanje.Awona macandelo abaluleke kakhulu kwindawo ye-Organelle ngamasuntswana ahlukeneyo, afana ne-α Amacandelo, amasuntswana axineneyo (δ Amacandelo) kunye ne-Lysosome ( λ Iinqununu, njl., jonga iThebhile 1 ngeenkcukacha.I-α Granules ziindawo zokugcina kwiiplatelet ezinokukhupha iiprotheni.Kukho ngaphezu kweshumi kwiplatelet nganye α Amacandelo.Itheyibhile 1 idwelisa kuphela amacandelo aphambili, kwaye ngokutsho kophando lombhali, kufunyenwe ukuba α Kukho amanqanaba angaphezu kwama-230 eeplatelet derived factor (PDF) ekhoyo kwiigranules.I-Dense particle ratio α Iincinci zincinci, kunye nobubanzi be-250-300nm, kwaye kukho i-4-8 ye-dense particles kwi-platelet nganye.Okwangoku, kufunyenwe ukuba i-65% ye-ADP kunye ne-ATP igcinwe kwiincinci ezixineneyo kwiiplatelet, kwaye i-90% ye-5-HT egazini nayo igcinwe kwiincinci ezixineneyo.Ke ngoko, amasuntswana ashinyeneyo abalulekile ekudityanisweni kweeplatelet.Ukukwazi ukukhulula i-ADP kunye ne-5-HT iphinda isetyenziswe kwikliniki ukuvavanya umsebenzi wokufihla iplatelet.Ukongeza, lo mmandla ukwaqulethe i-mitochondria kunye neLysosome, ekwayindawo yophando ekhaya naphesheya kulo nyaka.I-2013 Nobel Prize in Physiology and Medicine yanikezelwa kwizazinzulu ezintathu, uJames E. Rothman, uRandy W. Schekman, kunye noThomas C. S ü dhof, ngokufumanisa iimfihlelo zeendlela zokuthutha ze-intracellular.Kukho iindawo ezininzi ezingaziwayo kwimetabolism yezinto kunye namandla kwiiplatelet ngokusebenzisa imizimba ye-intracellular kunye neLysosome.
Indawo ekhethekileyo yenkqubo ye-membrane ibandakanya i-OCS kunye ne-dense tubular system (DTS).I-OCS yinkqubo yepayipi ye-tortuous eyenziwa ngumphezulu weeplatelets ezitshona ngaphakathi kweeplatelets, zandisa kakhulu indawo yeeplatelet ezidibana neplasma.Kwangaxeshanye, sisijelo esingaphandle kweseli yezinto ezahlukeneyo zokungena iiplatelet kwaye zikhuphe imixholo eyahlukeneyo yeeplatelet.Umbhobho we-DTS awuqhagamshelwanga kwihlabathi langaphandle kwaye yindawo yokwenziwa kwezinto ngaphakathi kweeseli zegazi.
2. Umsebenzi wePhysiological of Platelets
Umsebenzi oyintloko we-physiological of platelets kukuthatha inxaxheba kwi-hemostasis kunye ne-thrombosis.Imisebenzi esebenzayo yeeplatelet ngexesha le-physiological hemostasis inokwahlulwa ngokufanelekileyo ibe ngamanqanaba amabini: i-hemostasis yokuqala kunye ne-hemostasis yesibini.IiPlatelets zidlala indima ebalulekileyo kuzo zombini izigaba ze-hemostasis, kodwa iindlela ezithile ezisebenza ngazo zisahluka.
1) Umsebenzi wokuqala we-hemostatic weplatelet
I-thrombus eyenziwe ngexesha le-hemostasis yokuqala yi-thrombus emhlophe, kwaye ukuphendula okusebenzayo okufana nokunamathela kweplatelet, ukuguqulwa, ukukhululwa, kunye nokudibanisa ziindlela ezibalulekileyo kwinkqubo yokuqala ye-hemostasis.
I. Platelet adhesion reaction
Ukubambelela phakathi kweeplatelet kunye neendawo ezingezizo iiplatelet kubizwa ngokuba yi-platelet adhesion, okuyinyathelo lokuqala lokuthatha inxaxheba kwiimpendulo eziqhelekileyo ze-hemostatic emva kokulimala kwemithambo kunye nenyathelo elibalulekileyo kwi-thrombosis ye-pathological.Emva kokulimala kwe-vascular, iiplatelet ezijikelezayo kulo mkhumbi ziqhutywe ngumphezulu we-tissue phantsi kwe-vascular endothelium kwaye ngokukhawuleza zibambelela kwiifibers ze-collagen eziveziweyo kwindawo yokulimala.Ngemizuzu eyi-10, iiplatelet ezifakwe kwindawo zifikelele kwixabiso eliphezulu, zenza amahlule egazi amhlophe.
Izinto eziphambili ezibandakanyekayo kwinkqubo yokubambelela kwiplatelet ziquka i-platelet membrane glycoprotein Ⅰ (GP Ⅰ), i-von Willebrand factor (vW factor) kunye ne-collagen kwi-subendothelial tissue.Iintlobo eziphambili ze-collagen ezikhoyo kwindonga ye-vascular ziintlobo ze-I, III, IV, V, VI, kunye ne-VII, phakathi kweentlobo ze-collagen ze-I, III, kunye ne-IV zibaluleke kakhulu kwinkqubo yokubambelela kwiplatelet phantsi kweemeko ezihambayo.I-vW factor ibhuloho edibanisa ukunamathela kweeplatelet ukuthayipha i-I, III, kunye ne-IV ye-collagen, kunye ne-glycoprotein i-receptor ethile ye-GP Ib kwi-membrane yeplatelet yindawo ephambili yokubopha i-platelet collagen.Ukongezelela, i-glycoproteins GP IIb / IIIa, GP Ia / IIa, GP IV, CD36, kunye ne-CD31 kwi-membrane yeplatelet nayo ithatha inxaxheba ekunamatheleni kwi-collagen.
II.Platelet aggregation reaction
I-phenomenon yeeplatelet ezinamathela enye kwenye ibizwa ngokuba yi-aggregation.I-aggregation reaction yenzeke ngokuphendula ngokunamathela.Phambi kweCa2 +, iplatelet membrane glycoprotein GPIIb/IIIa kunye nefibrinogen aggregate dispersed platelets ndawonye.Udityaniso lwePlatelet lunokunyanzelwa ziindlela ezimbini ezahlukeneyo, enye zii-inducers zeekhemikhali ezahlukeneyo, kwaye enye ibangelwa kuxinzelelo lokucheba phantsi kweemeko ezihambayo.Ekuqaleni kokuhlanganisana, iiplatelets ziyatshintsha ukusuka kwidiskhi ukuya kwimilo engqukuva kwaye kuvele iinyawo ezingathi zifana nameva amancinane;Ngelo xesha, i-platelet degranulation ibhekisela ekukhululweni kwezinto ezisebenzayo ezifana ne-ADP kunye ne-5-HT eyayigcinwe ekuqaleni kwiincinci ezixineneyo.Ukukhutshwa kwe-ADP, i-5-HT kunye nokuveliswa kwezinye i-Prostaglandin kubaluleke kakhulu ekuhlanganiseni.
I-ADP yeyona nto ibalulekileyo kwiplatelet aggregation, ngakumbi i-endogenous ADP ekhutshwa kwiiplatelet.Yongeza inani elincinci le-ADP (ukugxilwa kwi-0.9) kwi-platelet suspension μ Ngezantsi kwe-mol / L), inokubangela ngokukhawuleza ukuhlanganiswa kweplatelet, kodwa ngokukhawuleza i-depolymerize;Ukuba iidosi ezimodareyitha ze-ADP (1.0) zongezwa μ Ngokumalunga ne-mol/L, inqanaba lesibini lokudibanisa elingenakuguquleka lenzeka kamsinya emva kokuphela kwesigaba sokuqala sokudibanisa kunye nesigaba se-depolymerization, esibangelwa yi-ADP engapheliyo ekhutshwe ngamaplatelets;Ukuba inani elikhulu le-ADP liyongezwa, ngokukhawuleza libangela ukuhlanganiswa okungenakuguqulwa, okungena ngokuthe ngqo kwisigaba sesibini sokuhlanganiswa.Ukongeza iidosi ezahlukeneyo ze-thrombin ekumisweni kweplatelet nako kunokubangela ukuhlanganiswa kweplatelet;Kwaye kufana ne-ADP, njengoko i-dosage ikhula ngokuthe ngcembe, ukuhlanganiswa okubuyiselweyo kunokubonwa ukusuka kwinqanaba lokuqala ukuya ekubonakaleni kwezigaba ezibini zokudibanisa, kwaye emva koko ungene ngqo kwisigaba sesibini sokuhlanganiswa.Ngenxa yokuba ukuthintela ukukhutshwa kwe-ADP engapheliyo kunye ne-adenosine kunokuthintela ukuhlanganiswa kweplatelet okubangelwa yi-thrombin, ibonisa ukuba umphumo we-thrombin unokubangelwa ukubotshwa kwe-thrombin kwi-receptors ye-thrombin kwi-membrane yeplatelet, ekhokelela ekukhululweni kwe-ADP engapheliyo.Ukongezwa kwe-collagen kunokubangela ukuba i-platelet aggregation imiswe, kodwa kuphela ukuhlanganiswa okungenakuguqulwa kwisigaba sesibini ngokubanzi kukholelwa ukuba kubangelwa ukukhululwa kwe-ADP engapheliyo ebangelwa yi-collagen.Izinto ezinokubangela ukudityaniswa kweeplatelet ngokubanzi zinokunciphisa i-cAMP kwiiplatelet, ngelixa ezo zithintela ukudityaniswa kweeplatelet zonyusa i-cAMP.Ngoko ke, ngoku kukholelwa ukuba ukuhla kwe-cAMP kunokubangela ukunyuka kwe-Ca2 + kwiiplatelet, ukukhuthaza ukukhululwa kwe-ADP engapheliyo.I-ADP ibangela ukudityaniswa kweplatelet, efuna ubukho beCa2+ kunye nefibrinogen, kunye nokusetyenziswa kwamandla.
Indima yeplatelet Prostaglandin I-phospholipid ye-platelet plasma membrane iqukethe i-Arachidonic acid, kunye neseli yeplatelet iqukethe i-Phosphatidic acid A2.Xa iiplatelet zisebenza kumphezulu, iPhospholipase A2 nayo iyasebenza.Ngaphantsi kwe-catalysis ye-Phospholipase A2, i-Arachidonic acid ihlukaniswe kwi-phospholipids kwi-membrane ye-plasma.I-Arachidonic acid inokwenza inani elikhulu le-TXA2 phantsi kwe-catalysis ye-platelet cyclooxygenase kunye ne-Thromboxane synthase.I-TXA2 inciphisa i-cAMP kwiiplatelet, okubangela ukuhlanganiswa kweplatelet eyomeleleyo kunye ne-vasoconstriction effect.I-TXA2 nayo ayizinzanga, ngoko iguquka ngokukhawuleza ibe yi-TXB2 engasebenzi.Ukongezelela, iiseli eziqhelekileyo ze-vascular endothelial ziqukethe i-prostacyclin synthase, enokuthi ibangele ukuveliswa kweprostacyclin (PGI2) kwiiplatelet.I-PGI2 inokunyusa i-cAMP kwiiplatelet, ngoko ke inempembelelo enamandla yokuthintela kwi-platelet aggregation kunye ne-Vasoconstriction.
I-Adrenaline inokugqithiswa nge-α 2. Ukudibanisa kwe-Adrenergic receptor kunokubangela ukuhlanganiswa kweplatelet ye-biphasic, kunye noxinzelelo lwe-(0.1 ~ 10) μ Mol / L.I-Thrombin kwiindawo eziphantsi (<0.1 μ Kwi-mol / L, isigaba sokuqala sokuhlanganiswa kweeplatelet sibangelwa ikakhulu yi-PAR1; Kwiindawo eziphezulu (0.1-0.3) μ Kwi-mol / L, ukuhlanganiswa kwesigaba sesibini kunokunyanzeliswa yi-PAR1 kunye ne-PAR4 Iinducers ezinamandla zokudityaniswa kweplatelet zikwaquka iplatelet activating factor (PAF), collagen, vW factor, 5-HT, njl njl. Udityaniso lwePlatelet lusenokwenziwa ngokuthe ngqo ngesenzo soomatshini ngaphandle kwe-inducer. i-atherosclerosis.
III.Ukusabela kokukhutshwa kwePlatelet
Xa iiplatelet ziphantsi kokuvuselelwa kwe-physiological, zigcinwa kwiincinci ezixineneyo α I-phenomenon yezinto ezininzi kwiinqununu kunye ne-lysosomes ekhutshwa kwiiseli kuthiwa yi-release reaction.Umsebenzi weeplatelet ezininzi ufezekiswa ngeempembelelo zebhayoloji zezinto ezenziwe okanye ezikhutshwe ngexesha lokukhululwa.Phantse zonke ii-inducers ezibangela ukudityaniswa kweplatelet zinokubangela ukusabela kokukhululwa.Ukusabela kokukhululwa ngokuqhelekileyo kwenzeka emva kwesigaba sokuqala sokudityaniswa kweeplatelet, kwaye into ekhutshwe yimpendulo yokukhululwa yenza ukudityaniswa kwesigaba sesibini.Ii-inducers ezibangela ukusabela kokukhululwa zinokwahlulwa ngokufanelekileyo zibe:
i.Inducer ebuthathaka: i-ADP, i-adrenaline, i-Norepinephrine, i-vasopressin, i-5-HT.
ii.Iinducers eziphakathi: TXA2, PAF.
iii.Iinducers ezinamandla: i-thrombin, i-pancreatic enzyme, i-collagen.
2) Indima yeeplatelet kwi-coagulation yegazi
IiPlatelets ikakhulu zithatha inxaxheba kwiindlela ezahlukeneyo zokuxilonga nge-phospholipids kunye ne-membrane glycoproteins, kubandakanywa i-adsorption kunye nokusebenza kwezinto zokudibanisa (izinto ze-IX, i-XI, kunye ne-XII), ukwakhiwa kwe-coagulation ekhuthaza ii-complexes kumphezulu we-phospholipid membranes, kunye nokukhuthaza ukubunjwa kweprothrombin.
I-plasma inwebu kumphezulu weplatelets ibophelela kwizinto ezahlukeneyo zokudityaniswa, ezifana ne-fibrinogen, i-factor V, i-factor XI, i-factor XIII, njl. njl. kunye nePF3 zombini zikhuthaza ukujija kwegazi.I-PF4 inokunciphisa i-heparin, ngelixa i-PF6 inqanda i-fibrinolysis.Xa iiplatelet zisebenza kumphezulu, zinokukhawulezisa inkqubo yokusebenza komphezulu we-coagulation factor XII kunye ne-XI.I-phospholipid surface (PF3) enikezelwa ngamaplatelets iqikelelwa ukuba ikhawuleze ukusebenza kweprothrombin ngamaxesha angama-20000.Emva kokudibanisa izinto ze-Xa kunye ne-V kumphezulu wale phospholipid, ziyakwazi ukukhuselwa kwimiphumo yokuvimbela i-antithrombin III kunye ne-heparin.
Xa iiplatelet zidibene ukuze zenze i-hemostatic thrombus, inkqubo yokudibanisa sele yenzekile kwindawo, kwaye iiplatelet ziye zaveza ubuninzi beendawo ze-phospholipid, zibonelela ngeemeko ezincomekayo kakhulu zokusebenzisa i-factor X kunye ne-prothrombin.Xa iiplatelet zikhuthazwa yi-collagen, i-thrombin okanye i-kaolin, i-Sphingomyelin kunye ne-Phosphatidylcholine ngaphandle kwe-membrane yeplatelet zijika kunye ne-phosphatidyl Ethanolamine kunye ne-phosphatidylserine ngaphakathi, okubangela ukwanda kwe-phosphatidyl Ethanolamine kunye ne-membrane ye-phosphatidyl phezu kwe-membrane ye-membrane ye-phosphatidyl.La maqela angasentla e-phosphatidyl ajike ngaphezulu kumphezulu weeplatelet athatha inxaxheba ekwenziweni kwee-vesicles kumphezulu we-membrane ngexesha lokwenziwa kweplatelet.I-vesicles iyahlukana kwaye ingena kwi-circulation yegazi ukuze yenze i-microcapsules.I-vesicles kunye ne-microcapsules zizityebi kwi-phosphatidylserine, enceda kwindibano kunye nokusebenza kweprothrombin kwaye ithatha inxaxheba kwinkqubo yokukhuthaza ukudibanisa kwegazi.
Emva kokuhlanganiswa kweplatelet, i-α yayo Ukukhululwa kwezinto ezahlukeneyo zeplatelet kwiinqununu zikhuthaza ukubunjwa kunye nokwanda kweefayili zegazi, kwaye zibambisa ezinye iiseli zegazi ukuze zenze ama-clots.Ke ngoko, nangona iiplatelet ziqhekeka ngokuthe ngcembe, i-hemostatic emboli isenokwanda.Iiplatelet ezishiywe kwihlwili legazi zinepseudopodia ezithi zidlulele kuthungelwano lwefibre yegazi.Iiproteni zekhontrakthi kwezi zivumelwano zeplatelet, zibangela ukuba ihlwili legazi lirhoxe, likhuphe i-serum kwaye libe yiplagi eqinileyo ye-hemostatic, itywine ngokuqinileyo i-gap yemithambo.
Xa i-platelet isebenze kunye ne-coagulation system phezu komhlaba, iphinda isebenze inkqubo ye-fibrinolytic.I-Plasmin kunye ne-activator yayo equlethwe kwiiplatelet iya kukhutshwa.Ukukhutshwa kwe-serotonin kwimicu yegazi kunye neeplatelet kunokubangela ukuba iiseli ze-endothelial zikhulule ii-activators.Nangona kunjalo, ngenxa yokuchithwa kweeplatelet kunye nokukhululwa kwe-PF6 kunye nezinye izinto ezivimbela i-proteases, azichatshazelwa ngumsebenzi we-fibrinolytic ngexesha lokubunjwa kwegazi.
(Imixholo yeli nqaku ishicilelwe, kwaye asiboneleli nasiphi na isiqinisekiso esicacileyo okanye esichaziweyo sokuchaneka, ukuthembeka okanye ukugqibelela kokuqulathwe kweli nqaku, kwaye abanaxanduva ngezimvo zeli nqaku, nceda uqonde.)
Ixesha lokuposa: Jun-13-2023