MCLC5.1.Thtnguynliuvmtsquytrnhgitmgiasc,giacm......................................25.1.1Quytrnhgitmln,cu.......................................................................................25.1.2Quytrnhgitmtru,b........................................................................................35.1.3Quytrnhgitmgiacm........................................................................................45.1.4nhhngcakthutgitmlnchtlngtht................................................45.2.Thnhphnvcutrccatht......................................................................................65.2.1Thnhphncatht.......................................................................................................65.2.2Mc.............................................................................................................................75.2.2.1.Cutrccamc...............................................................................................75.2.2.2.Cutrccasic(tboc).............................................................................85.2.2.3.Cutrccavisic(myofibril)........................................................................95.2.2.4.Cutocaxc(myofilament).......................................................................115.2.2.5.Thnhphnproteinc........................................................................................135.2.3.Mm........................................................................................................................155.2.4.Mlinkt..................................................................................................................175.2.4.1Sicollagen.........................................................................................................175.2.4.2Sielastin............................................................................................................175.3.Binihasinhthtsaugitm..............................................................................175.4.Musccathtvmtsphngphpnnhmusctht.....................................225.4.1Scttht................................................................................................................225.4.2Sbinimusccathtti...........................................................................265.4.3.Nhngyutnhhngnmusccatht.....................................................285.5.Phnloichtlngtht................................................................................................345.5.1.Thtbnhthng,thtPSE,thtDFDvccyutnhhng.............................345.5.2.Mtsphngphpbovmusccathtti................................................355.6.Cutrccathtvnhhngcasnunngncutrc....................................395.6.1Ccyuttrckhigitm..................................................................................395.6.2Ccyutsaukhigitm.....................................................................................405.6.3nhhngcasnunngncutrccatht...............................................405.7Khnngginccatht............................................................................................445.7.1Ncvchtlngtht..........................................................................................445.7.2.Ccyutnhhngnkhnngginccatht.........................................46TILIUTHAMKHO............................................................................................51
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5.1.Thtnguynliuvmtsquytrnhgitmgiasc,giacm5.1.1Quytrnhgitmln,cu
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5.1.2Quytrnhgitmtru,b
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5.1.3Quytrnhgitmgiacm
5.1.4nhhngcakthutgitmlnchtlngthta.KthutgychongBtcphngphpnogychongthtrckhihthtulyutgystresschoconvt.Chnhvldony,cngimthiutiastresstonnbngcchtinhnhthaotcchnhxc,nhanhvhiuqu.Nukhng,thtcbiuhinPSE(Pale,Soft,Exsudativerdch,mmvtimu),ccctnhchcnngcaproteingim,chtlngkthutcathtgimvnhvythtnguynliukhngthchhpchochbin.b.KthutlyhuytViclyhuytcthchinngmchcnhvtnhmchcnh.Vtctphinhtrnhsnhimbnsau.Viclyhuytdnnvicloinguncungcpoxytmu,kchthchsphngiiglycogenthnhaxitlacticlmgimpHcaquytht.Tincaqutrnhphngiinytythucvonhiuyutnhkthutgitm,bnchtquytht,nhitboqunquytht,...Viclyhuytphictinhnhngay,ttnhtltrongphacocngvkhithbttnh.Btcmtschmtrnocngugynhhngnchtlngtht.NuthvngvymnhtrckhichtssinhnhiuaxitlactictchlytrongquythtlmstgimnhanhpHmcsaukhihtht.Nukhnglytitnhanh,thtcghinhn
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cbiuhinxuthuyttrncnhmlnvibiuhinbnhlc.Hintngxuthuytnynhnthynhiutrnthmtsovithkhemnh.
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5.2.Thnhphnvcutrccatht5.2.1ThnhphncathtThtlloithcphmchnhthnhbngcchgiacngthchngccscthtnguynvn,hoclmtbphnscthtcaccloigiasc,giacm(NguynNgcTun<hanhHin,2004).
Vphngdinsinhlvmhc,ngitachiathtrathnh:mc,mlinktvtonbbinthcan,mmu,mthnkinhvbchhuyt.Tuynhintrongcngnghipthcphmvthngnghip,ngitaphnloikhngchdatrnccchcnngsinhlmcndatrnccgitrsdng,chonnthnhphncathtcchiathnh:-Mc-Mm-Mlinkt-Mxng-sn
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LoimThtbThtheoThtcuMcMmMlinktMxng-snMmu57-623-169-1217-290,8-140-6215-406-88-180,6-0,849-584-187-1118-380,8-1-MmuTlcaccmnitrntrongccloithtkhcnhauctrnhbytrongbng5.1.Bng5.1:Tl(%)caccmtrongccloitht(tnhtheokhilngthtx)
(Ngun:NguynNgcTun<hanhHin,2004)Mcvmmcxemlcgitrsdngcaonhttrongccloim.Thnhphncathtphthucvoloi,ging,giitnh,tui,iukinchmscvnuidngconvtcngnhnhngthayisaukhigitmxuthintrongmditcdngcaenzyme,visinhvt,thnhphnkhngkh,vccyutkhc(NguynVnMi,2006).
5.2.2Mc
5.2.2.1.CutrccamcTonbhctrongcthngvtcchiathnh2nhmln:cvnvctrn.Trongngnhthcphm,cvncquantmnghincuvchngchimtllnnhttrnthntht,lnguncungcpproteinvacidaminthityuchonhucudinhdngconngi.
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Hnh5.1.CutrccamcQuanstmtbpcctngang(hnh5.1),mimchocbpccbaobcbnngoibimtmnglinkt,gilmngngoibpc(epimysium).Bntrongbpccchiathnhnhiubcbc1,bc2vbc3.Mibccphnchiaringbitvbaobcbimtmnglinktgilmngbaoquanhbsic(perimysium).Trongccbsic,misicctchringlnhaunhlpmlinktmnggilmngtrongc(endomysium).
5.2.2.2.Cutrccasic(tboc)Sicchnhtr,hnhbpmnghochnhthoi,thonhaiuvckchthcln.Mtsiccngknhtrungbnhkhong50mvdikhong50mm.Cnggingnhccloitbokhc,xungquanhsiccbaobcbilpmngsiccngilsarcolemma.Nhngngcliviccloitbokhc,tbocccutrcanhn.Nhncasicnmbngoicasic,thnglnmngaydilpmng
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sic.ChydctheochiudicasiclhthngviqunT(T-tubules)baovngquanhtheochiungangsic.Phncutolnnhtchimkhong80-90%cutrcsiclccvisic(myofibrils).Phnnhcnliltyth(1-5%)vhthngmnglictng(sarcoplasmicreticulum)(hnh5.2).
Hnh5.2CutrccahthnglictngvngviqunT
5.2.2.3.Cutrccavisic(myofibril)Diknhhinviintccvisiccnhnthyphnbitbiccbngti(Aband-Anisotropic)vbngsng(Iband-Isotropic)phnbsutchiudisic(Hnh5.3).nvcutrcnhnhtcutonnsiccgilnvhtc(sarcomere)hocnvcocvn.
MtnvhtccgiihnbihaivchZgnnhauvchngccutothailoisimnhckchthcphntkhcnhaugilxc(myofilament).Hailoixcnylxcdymyosinvxcmngactin.Hailoixcnyspxptheomttrnhtcbitanxennhautheochiudccavisic.
Quansthnh5.3,xcdymyosinnmtrungtmca hat cosarcomerevkhnggnvovchZ,cxcnhlbngtiA.Trongkhi,xcmngactinkoditvchZvcmtphnlngvoccxcdymyosin.BngtiIcxcnhlvngnm
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giavchZvphncuicngcaxcdymyosin.
Trongsutqutrnhvnngvcoccangvt,chiudicabngtiAvnkhngthayitrongkhichiudicabngsngIsbngnli.iunycxemlmtquylutcbndnnlthuytgiithchscoc.
TrongbngtiA,khongcchgiahaiumtca2xactinlintipnhaucgilbngH.BngHlmtphncasarcomeremchcsixcdymyosinvkhngcphngnvoxactin.NmgiabngHvcngltrungtmcasarcomerelngMchnhthnhtcccutrcsiccmnhvcvaitrniccxmyosinvinhautheochiungangcavisic.
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Hnh5.3Cutrccavisic(myofbril)(Ngun:http://www.apsu.edu/thompsonj/Anatomy)
5.2.2.4.Cutocaxc(myofilament)
Xmng:Actinlthnhphnchnhcaxcmng.Xmngccutot300phntactinhnhcu(G-actin),gmhaichuipolypeptidxontheokiualpha(Hnh5.4).Trnchuixonkpny2phntTroponinvTropomyosinnhtheomttrnhtnhtnhtothnhphchpTroponinvTropomyosin.Xmngcngknh5-7nmvdikhong1m.
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Hnh5.4.Cutrccaxactin(Ngun:http://www.apsu.edu/thompsonj/Anatomy)
XdyMyosinlthnhphnproteinchyucutonnxdy.Myosinlproteinhnhsickhilngphntlnkhong520Kdavcchiudiphntkhong170nm.Mtphntmyosinbaogm2chuipolypeptidsxonalpha,haiumyosinnngixnghnhcuvhaicpmyosinnhnhcbiudintronghnh5.5.Phnuidilmtcunxonalpha.
Hnh5.5Cutrccamtphntmyosin
hpthnhxcdyccphntmyosinspxpthnhbvinhau.Ccuphnhhngvutdocaxdy,cnuthonhngvimgiacaxc,ngthichngspxpthnhtngimtdctheochiudicaxdysaochokhongcchcahaiiktipl14,3nmvlchvotrongkhnggian120(Hnh5.6)(NguynNgcTunvLThThanhHin,2004).
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Hnh5.6.Mtphnxcdymyosin(Ngun:http://www.apsu.edu/thompsonj/Anatomy)
Trongmtnvhtc,uphnhcaphntmyosinhunhgnstvixactin.Khicoc,phntmyosinkthpviactintothnhphchpactomyosin(hnh5.7).mixcmyosinckhong300-310uphnhnhngchckhong10-20%uphnhnylinktviactinkhicoc(NguynNgcTunvLThThanhHin,2004)
Hnh5.7:Skthpcaactinvmyosintrongqutrnhcoc
5.2.2.5.ThnhphnproteincNhccpphntrccutrccamcrtphctp.Ngoiactinvmyosinl2proteincbncutonnmcmcncmtslnglnccthnhphnproteinkhcnhtitin,tropomyosin,troponin,M-protein,C-protein,Ccproteinnyngvaitrquantrngtrongcutrccamccngnhkimsothotngcoc.Bng5.2diychobithmlngvvtrcamtsproteincutonnmc
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ProteinHmlng(%)VtrKhilngphnt(kDa)MyosinActinTitinTropomyosinTroponinNebulin-actininM-proteinC-proteinMyomesin-actininH-proteinCcproteinkhc452085532221