Sebopeho le Mosebetsi oa Li-platelet
Li-platelet, kapa li-platelet tsa mali, ke likaroloana tse nyane tsa lisele tse fumanoang maling 'me li ameha ts'ebetsong ea ho hoama ha mali (hemostasis). Ke karolo ea bohlokoa ea tsamaiso ea potoloho ea mali ea motho, e bapala karolo ea bohlokoa ho emiseng ho tsoa mali le ho qala pholiso ea maqeba. Sehloohong sena, re tla hlahloba sebopeho le mosebetsi oa li-platelet ka botebo, hammoho le bohlokoa ba tsona ho bolokeng bophelo bo botle ba 'mele ka kakaretso.
Tšimoloho le Tlhahiso ea Li-platelet
Li-platelet li simoloha liseleng tse kholo tse bitsoang megakaryocytes mokong oa masapo. Li-megakaryocytes ke lisele tse kholo haholo le tse rarahaneng, tse bophara ba tsona bo fihlang ho li-micrometer tse 100. Lisele tsena li hlahisa li-platelet ka ho lokolla likaroloana tse nyane tsa cytoplasm ea tsona maling. Ts'ebetso ena e laoloa ke lintlha tse fapaneng tsa kholo le lihormone, ho kenyeletsoa le thrombopoietin, e hlasimollang tlhahiso le kholo ea li-megakaryocyte.
Hang ha li hlahisitsoe, li-platelet li potoloha maling matsatsi a ka bang 7 ho isa ho a 10 pele li senngoa ke tsamaiso ea reticuloendothelial, haholo-holo spleen le sebeteng. Ka tloaelo, palo ea li-platelet maling e tloha ho 150.000 ho isa ho 450.000 ka microliter. Palo e tlase ea li-platelet e bitsoa thrombocytopenia, ha palo e phahameng ea li-platelet e bitsoa thrombocytosis.
Sebopeho sa Liplatelete
Li-platelet li na le sebopeho se ikhethang le se rarahaneng ho sa tsotellehe boholo ba tsona bo bonyenyane, se bophara ba di-micrometer tse 2 le tse 3. Sebopeho sa tsona se na le dikarolo tse mmalwa tse ka sehloohong:
1. Lera la Plasma: Lera le ka ntle la li-platelet, le nang le li-receptor bakeng sa limolek'hule tse fapaneng tsa lipontšo, ho kenyeletsoa collagen, fibrinogen, le lintlha tsa kholo. Lera lena le boetse le tšehetsa li-glycoprotein tse bapalang karolo ea bohlokoa ho kopaneng ha li-platelet le ho khomarela mabota a methapo ea mali e lemetseng.
2. Cytoplasm: Karolo e ka hare ea platelet e nang le li-organelle le meaho e fapaneng, ho kenyeletsoa mitochondria, lysosomes, le granules. Li-granules tsena li na le li-granules tsa alpha, tse nang le liprotheine tsa coagulation tse kang fibrinogen le growth factors, le li-dens granules, tse nang le limolek'hule tse kang ADP le calcium tse bapalang karolo ho activation ea platelet.
3. Lerako la masapo: Marangrang a diprotheine tse bopehileng ka hara diplatelete tse fanang ka sebopeho le tshehetso ya mechine. Dikarolo tse ka sehloohong tsa lerako lena la masapo di kenyeletsa actin le di-microtubules, tse dumellang diplatelete ho fetola sebopeho sa tsona nakong ya ho kenngwa tshebetsong le ho kopanngwa.
4. Sistimi ea Mokero o Bulehileng le Sistimi ea Mokero o Teteaneng: Libopeho tsa lera la ka hare tse sebetsang polokelong le tokollong ea limolek'hule tsa lipontšo. Sistimi ea mokero o bulehileng e buisana le bokantle ba sele 'me e thusa ho lokolloeng ha lintho tse nang le granule, ha sistimi ea mokero o teteaneng e bapala karolo polokelong ea calcium le taolong ea maemo a calcium ka hare ho sele.
Mosebetsi oa Liplatelete
Li-platelet li na le mesebetsi e 'maloa ea bohlokoa e amanang le ho hemostasis le pholiso ea maqeba:
1. Sebopeho sa Polaka ea Liplatelete
Ha mothapo wa madi o lemetse, collagen le tissue factor tse tswang ho matrix e pepeneneng ya kantle ho sele di qala ho sebetsa hanghang. Diplatelete tse sebetsang di fetola sebopeho, di ba tse kgomarelang, mme di kgomarela lebota la mothapo o lemetseng. Di boetse di qala ho lokolla dikahare tsa di-granule tsa tsona, ho kenyeletswa le di-coagulation factor le dimolekhule tse ding tsa matshwao tse hohelang diplatelete tse ngata sebakeng sa kotsi.
Ts'ebetso ena e fella ka ho thehoa ha plagi ea pele ea platelet e emisang ho tsoa mali ka nakoana. Ena ke mohato oa pele oa hemostasis ea mantlha, e thibelang tahlehelo e feteletseng ea mali ho fihlela mekhoa ea bobeli ea ho kopanya mali e ka etsa hore ho be le ho khomarela ho tsitsitseng haholoanyane.
2. Tokollo ea Babuelli ba Lik'hemik'hale
Ha di qala ho sebetsa, di-platelet di lokolla di-mediator tse fapaneng tsa dikhemikhale ho tswa ho di-granule tsa tsona. Di-granule tsa Alpha di lokolla diprotheine tse kang fibrinogen, platelet growth factor (PDGF), di-coagulation factor, kininogen, le vWf (von Willebrand factor), tse tlatsetsang ho kopaneng ha di-platelet le ho tsitsisa di-platelet plug. Di-granule tse nang le di-dense di lokolla dimolek'hule tse nyane tse kang ADP, ATP, serotonin le calcium, tse bapalang karolo ho vasoconstriction, di hohela di-platelet tse ngata sebakeng sa kotsi, mme di eketsa ho sebetsa ha di-platelet.
Mohlala, ADP e tlamahana le receptor ea P2Y12 holim'a platelet, e baka liphetoho tsa sebopeho sa platelet, e eketsa kamano ea tsona le fibrinogen, 'me e matlafatsa likamano lipakeng tsa liplatelet, e leng se fellang ka ho kopana ho matla. Khalsiamo e bapala karolo ea bohlokoa mehatong e fapaneng ea ho kopana, e thusa ho theha li-enzyme tse rarahaneng holim'a platelet.
3. Ho hoama le ho thehoa ha Fibrin
Ntle le ho theha polaka ea platelet le ho lokolla bathusi, li-platelet li boetse li khothalletsa ho thehoa ha fibrin, e leng protheine e matlafatsang le ho tsitsisa polaka ea platelet. Li-platelet tse sebetsang li fana ka bokaholimo bo nolofalletsang tšebelisano ea lintho tse kopanyang mali litseleng tsa ka hare le tsa kantle, e leng se qetellang se lebisa phetohong ea fibrinogen e qhibilihang ho ba fibrin e sa qhibiliheng. Joale fibrin e theha marang-rang a tšoasang lisele tse khubelu tsa mali le lisele tse ling maling, e leng se etsang hore mali a qhibilihe ka mokhoa o tsitsitseng.
4. Pholiso ea Maqeba
Ntle le karolo ea tsona ho hemostasis, li-platelet le tsona li kenya letsoho ts'ebetsong ea pholiso ea leqeba. Lintho tse hlahisang kholo tse lokolloang ke li-platelet, tse kang PDGF, vascular endothelial growth factor (VEGF), le transforming growth factor-beta (TGF-β), li susumetsa ho ata le ho falla ha lisele ho ea sebakeng sa leqeba, ho kenyeletsoa le li-fibroblast, lisele tsa endothelial le lisele tsa epithelial. Ts'ebetso ena e thusa ho thehoeng ha lisele tse ncha le methapo ea mali (angiogenesis), e leng ea bohlokoa bakeng sa pholiso e atlehang ea leqeba.
Mathata a Platelet
Ho se sebetse hantle kapa ho se tloaelehe ha palo ea li-platelet ho ka baka mathata a fapaneng a bophelo bo botle:
– Thrombocytopenia: Palo e tlase ea li-platelet e ka lebisa ho tsoa mali a mangata hoo ho leng thata ho ho emisa. Boemo bona bo ka bakoa ke mabaka a fapaneng, ho kenyeletsoa mafu a 'mele a itšireletsang mafung, tšoaetso, kapa litla-morao tsa meriana.
– Thrombocytosis: Palo e phahameng ea li-platelet e ka eketsa kotsi ea ho thehoa ha mali a thibaneng, e leng se ka lebisang ho stroke kapa tlhaselo ea pelo. Lisosa li ka kenyelletsa mathata a myeloproliferative, karabelo ea tšoaetso kapa ho ruruha, kapa karolo ea lefu le sa foleng.
– Ho se sebetse hantle ha liplatelete: Liplatelete tse sa sebetseng hantle, leha palo ea tsona e le e tloaelehileng, le tsona li ka baka mathata a ho tsoa mali, joalo ka mafu a mang a liphatsa tsa lefutso kapa ka lebaka la meriana e itseng.
Qetello
Li-platelet li bapala karolo ea bohlokoa tsamaisong ea potoloho ea mali le ho hemostasis. Ke karolo ea bohlokoa ea mokhoa oa ho itšireletsa oa 'mele khahlanong le ho tsoa mali' me li na le mesebetsi e meng ho foliseng maqeba. Kutloisiso e eketsehileng ea li-platelet, maemong a tloaelehileng le a pathological, e bohlokoa bakeng sa thibelo le kalafo ea mafu a fapaneng a mali. Lipatlisiso li ntse li tsoela pele ho hlahloba likarolo tse fapaneng tsa li-platelet, ho kenyeletsoa le bokhoni ba tsona kalafong ea bongaka le litšebelisong tsa bongaka.
