Le indlela imisipha. Imisebenzi kunye neempawu umsipha skeletal

Muscle nokuncipha - yinkqubo entsonkothileyo eziquka inani izigaba. Awona macandelo aphambili apha myosin, actin, troponin, tropomyosin kunye actomyosin, kunye ion calcium kunye nemixube ezibonelela amandla kwezihlunu. Qwalasela iintlobo kunye ezisebenza imisipha. Makhe sifunde, zenziwe apho kwaye amanyathelo ayimfuneko ukwenzela inkqubo nokungazinzi koqoqosho.

imisipha

Izihlunu zidityanisiwe ngokwamaqela, banayo indlela efanayo imisipha. Ngendlela efanayo ukuba zohlulwa ngokwendidi 3:

• izihlunu striated umzimba;
• izihlunu striated ye imithambo kunye ventricles zentliziyo;
• amalungu kwemisipha egudileyo, imithambo yegazi nolusu.

izihlunu Striated ziyinxalenye yenkqubo musculoskeletal, ukuba ube yinxalenye yale nto, kuba ngaphandle kwabo, oku kuquka imisipha, nemisipha, amathambo. Xa ukuphumeza indlela imisipha, yenze le misebenzi ilandelayo kunye nemisebenzi:

• lihamba umzimba;
• amalungu omzimba kunqwenela kuthelekiswa omnye komnye;
• umzimba kuyaxhaswa kwisithuba;
• ubushushu eyakhiwe;
• neuron luvuliwe yi afferent emasimini abanomdla imisipha.

Zihlunu Smooth:

• motor izixhobo amalungu angaphakathi, equka umthi inyumoniya, imiphunga kunye tube ukudla;
• emithanjeni kunye yegazi ezikwiinkqubo;
• inkqubo amalungu enzala.

iipropati bokuphila

Njengazo zonke ekuyo emzimbeni womntu kukho kwiipropati ezintathu ibalulekileyo kwimicu umsipha skeletal:

• contractility - ukunciphisa utshintshe ombane xa yitile;
• conductivity - movement amandla kulo lonke ifayibha;
• excitability - ephendula kwizivuseleli ngokuguqula inwebu olunokubakho ion permeability.

Izihlunu banovuyo kwaye uqale ukuhla nge inkqubela-luvo evela kwiziko. Kodwa phantsi kweemeko ngumntu usebenzisa zovuselelo zombane. Umsipha ngoko wacatshukiswa ngqo (ukuvuselela ngqo) okanye nge esihlunwini luvo innervating (ukuvuselela ngqo).

iintlobo emanxebani

Indlela of kwemisipha kuthetha ukuguquka amandla ekhemikhali imisebenzi ngoomatshini. Le nkqubo lingaba nokulinganiswa ngokomfuniselo ne frog: ithole umthwalo kwezihlunu kwakhe ubunzima ephantsi, uze ukubacaphukisa electroimpulses ukukhanya. Ukwehla, apho umsipha iba elifutshane, ebizwa isotonic. kunciphisa kwenzeka nokuncipha xa ulwandiso. Imisipha musa ukuvumela uphuhliso amandla izihlunu iyanqanyulwa. Enye indlela auksotonichesky of imisipha ibandakanya iimeko leenzingo xa izihlunu shortens indlela ncinane, kwaye namandla ukufikelela ubuninzi.

Isakhiwo innervation kwemisipha skeletal

I striated umsipha skeletal iquka iintlobo imicu kwizicwili yaye zigxunyekwe imisipha. Kwezinye Imicu kwezihlunu zicwangciswe ngaxeshanye esqwini elide, kwaye kwezinye izimvo elibhalwe ngokumileyo, ukuba incamathele kwi imicu tyazhu kunye pinnate uhlobo central.

Eyona iphambili ifayibha na ubunzima sarcoplasm imicu emihle - myofibrils. Bona iindawo eziqaqambileyo kwaye kumnyama beman 'omnye nomnye, lo gama imicu ezikufutshane striated ezi egungxula - in cross-candelo. Oku kuphumela cross-nisishiye ngeenxa imicu kwezihlunu.

Sarcomere uya kuba kukukhanya disks ezintsonkothileyo, emnyama kunye amabini, kwaye akhawulwe imigca ezimile-Z. Sarcomeres - a izixhobo contractile imisipha. Kubonakala ukuba ifayibha contractile kwezihlunu siquka:

• izixhobo contractile (myofibrils system);
• izixhobo trophic ne mitochondria, Golgi ezintsonkothileyo buthathaka reticulum endoplasmic ;
• isixhobo ndizayo;
• izixhobo reference;
• izixhobo luvo.

Muscle ifayibha yahlulwe 5 kunye neziseko zazo kunye nemisebenzi, kwaye uyinxenye ijwabu kwezihlunu.

innervation

Le inkqubo kwimicu izihlunu striated iqaphelwa luvo, ezizezi axons iineuron lwemoto le spinal intambo nobuchopho stem. Enye motoneuron innervate Imicu kwezihlunu eziliqela. Complex kunye motoneuron neerhali izihlunu innervated ngokuba neuromotor (HME) okanye iyunithi isithuthuthu (MU). Umyinge Inani zomzimba, innervates a motoneuron, ubonakalise DE izihlunu, ebizwa kwintembeko innervation mninzi. Le yokugqibela yeyona inkulu zezihlunu, iintshukumo apho ezincinane 'obhityileyo "(amehlo, iminwe, ulwimi). ixabiso layo lincinane, phezu koko, xa izihlunu kunye isindululo "indawo" (umz, esifubeni).

Innervation kunokuba abangatshatanga kunye ezininzi. Kwimeko yokuqala kubhaliwe ndaqonda neziphelo motor compact. Ngokuqhelekileyo oku okufana luvo motor enkulu. Imicu Muscle (ebizwa kulo mzekelo, ngokwasemzimbeni, okanye fast) ovelisa PD (nekhono action) ezisebenza kuzo.

innervation Multiple kwenzeka, umzekelo, xa izihlunu iliso lwangaphandle. Oku asinto amandla isenzo eyenziwe, ekubeni inwebu akukho amajelo sodium electroexcitability. Bona kuzo ifayibha depolarization ye iziphelo zobuchopho. Oku kuyimfuneko ukuze uvule indlela yokuba imisipha. Le nkqubo apha ayikho ngokukhawuleza njengoko kwimeko yokuqala. Ngoko ke, oko kuthiwa kade.

Ubume bale myofibrils

uphando ifayibha kwemisipha wenziwe namhlanje ngenxa yokuba X-reyi diffraction, electron microscopy, kunye neendlela histochemical.

Oku kubalwa ukuba myofibril nganye, netoti nto-1 micron, kuquka malunga nama-2,500 protofibrils, ngamanye evuthelweyo polymerized iiproteni iimolekyuli (actin kunye myosin). protofibrils Actin myosin kabini thinner. Nokuphumla, ezi izihlunu ibekwe kangangokuba iincam actin cingwana ukungena kulo izithuba phakathi protofibrils myosin.

A strip imxinwa ukukhanya kwediski A ukhululekile kwayo actin. A inwebu Z ibamba kunye.

On myosin zixhobo kufuneka lunamaqoqo ezinqamlezayo ukuya ku-20 NM, kwi iintloko leyo malunga 150 iimolekyuli myosin. Zimke biopolyarno, kunye myosinic intloko nganye kanga olu cingwana actin. Xa kukho uxinezeleko phezu kwayo kwamaziko actin myosin, actin ntambo likufutshane embindini sarcomere. Ekupheleni kwayo myosin zifike Z. umgca Emva koko uthathe lonke sarcomere, kunye actin uphakathi kwabo. Ngelo xesha ndiya kubagxotha ubude lifinyele, yaye ekugqibeleni iyalahleka ngokupheleleyo, kunye noko Z umgca uba mkhulu.

Ngoko ke, ngokutsho kwithiyori ihamba nebomvu, ngenxa kuncitshiswa ubude imicu kwezihlunu. Ithiyori, ebizwa ngokuba "nezixhobo", waphuhliswa Huxley kunye Hanson phakathi kwinkulungwane yamashumi amabini.

Indlela kwemisipha ifayibha nokuncipha

Imfundiso ephambili kukuba akukho filament (myosin kunye actin) kukuncwina. ubude babo kuhlala ingatshintshanga kunye izihlunu akhululeke. Kodwa iinyanda zixhobo ezingcakacileyo, n'ekiweebwayo, hamba phakathi kwayo shinyi, kunciphisa iqondo ukudibana, ngoko kukho ukwehla.

Indlela molekyuli ye kwemisipha na ngolu hlobo lulandelayo ngokuwatshibiliza kwayo actin. intloko Myosin ehlobene protofibrils kunye actin. Kunye amathambeka zabo sliding apho, ukuhambisa actin olulingana ukuya embindini sarcomere. Ngenxa umbutho vuvabyi neemolekyuli myosin kumacala omabini kwayo, iimeko ongulo zixhobo actin kumacala ahlukeneyo.

Xa izihlunu zokwehlisa myosin intloko ihambisa kude kwayo actin. Ne iphetshana lula ekhululekile ukuqina kwezihlunu enqaba ngaphantsi kakhulu. Ngoko ke, ukuba nje ixesha elide.

amanyathelo zokunciphisa

Indlela of kwemisipha zingaphawulwa ngokufutshane yahlulwe manqanaba alandelayo:

1. Muscle ifayibha iyavuseleleka xa amandla isenzo ikhutshwa ukusuka luvo mafutha le leesynapse.
2. Isakhono isenzo eyenziwe kwi-inwebu le ifayibha izihlunu, yaye ke ukuba kuye kwanwenwa myofibrils.
3. pair electromechanical esigcwalisiweyo emele uguqulelo lombane zibe ngoomatshini PD sliding. Oku ngokuyimfuneko ibandakanya ion calcium.

ion calcium

Kuba ukuqonda ngcono inkqubo ifayibha ukusebenza ion calcium kulula ukuqwalasela ulwakhiwo olu cingwana actin. Ubude bayo 1 micron, ubukhulu - 5 ukuya 7 NM. Oku iperi imisonto, ephothiweyo, zazo le monomer actin. Phantse wonke NM 40 apha ukulenza troponin molecule, naphakathi imixokelelwane - tropomiozinovye.

Xa ion calcium abangekhoyo, okt myofibrils ukuphumla iimolekyuli tropomiozinovye elide zivala i-attachment xo actin kunye kwo myosin. Kodwa xa ion calcium yasebenza tropomiozinovye iimolekyuli ukuthi xumbu kwayo kwiindawo ezinzulu nevulelekileyo.

Ke iibhulorho myosin ziqhotyoshelwe zixhobo actin kunye nobanda ATP kwaye kuphuhlisa amandla kwezihlunu. Oku kunokwenzeka ngenxa yokuba ifuthe calcium troponin. Kulo molecule le yakamva gqitha, ngokwenjenjalo nokudobelela tropomyosin.

Xa umsipha ekhululekile, kungenxa 1 gram ubunzima emanzi iqulathe ngaphezulu kwe-1 mmol ngecalcium. iityuwa calcium izibonelelo zokugcina ekwanti okhethekileyo. Kungenjalo, imisipha kuya kusoloko enqaba.

calcium efakwe ngolu hlobo. Kwiindawo ezahlukeneyo iiseli uvalo kwezihlunu ngaphakathi ifayibha ezi ngemibhobho apho kukho unxulumano kunye nokusingqongileyo ngaphandle iiseli. Le inkqubo tubules ezinqamlezayo. A nkqubo aa Incopho eziphelweni longitudinal apho - vesicles (terminal) amatanki zilungiswe kufutshane kwinkqubo ezinqamlezayo diaphragms. Kunye wafumana triad. Kwaba ngo ezineengqayi egcinwe calcium.

Ekubeni PD isasazwa kulo yeseli, kwaye kukho conjugation electromechanical. Excitation ingena ifayibha engena longitudinal kukhupho inkqubo calcium. Ngoko ke indlela zokunciphisa yenziwa imicu kwezihlunu.

3 Inkqubo ne ATP

Xa intsebenziswano omabini imisonto phambi ikhalsiyam ion indima eninzi ATP. Xa ukusebenzisa indlela zihlunu yindibanisela izihlunu skeletal, amandla ATP iyasetyenziswa:

• ukusebenza sodium kunye nempompo potassium leyo ligcina xi rhoqo ion;
• ezi zinto kwi kumacala ahlukeneyo ndizayo;
• ngokuhambisa zixhobo kunciphisa myofibrils;
• Impompo calcium umsebenzi obambeleyo ukuphumla.

ATP ukho kule inwebu yeseli, bemicu myosin kunye imifinya reticulum sarcoplasmic. Enzyme sokudiliza zilahlwe myosin.

ungadli ATP

Yinto eyaziwayo ukuba iintloko myosin basebenzisane actin kwaye oqulethe izinto zokwenza okufunwa cleavage ATP. actin isebenze Last kunye myosin phambi ion wemagniziyam. Ngoko enzyme cleavage lwenzeka xa eqhotyoshelwe entloko myosin actin. Okuya uba mkhulu umsantsa ezintlanganweni iibhulorho, isantya kukwahlukana liya kuba ngaphezulu.

ATP mechanism

Emva kokugqitywa intshukumo AFL molecule inika amandla ngokuba ukwahlula basabela njani inxaxheba actin kunye myosin. intloko Myosin ehlukanisiwe, ATP ke lwanamathela phosphate kunye ADP. Isiphelo entsha idityanisiwe ATP molecule kwaye nomjikelo ikhala. Leyo ke indlela imisipha nokuphumla kwinqanaba eziphilayo.

Umsebenzi cross-kwo ziya kuhlala kuphela logama nje haydrolisis ATP kwenzeka. Ukuba asithe iibhulorho enzyme akayi iqhotyoshelwe kwakhona.

Xa kuqala ukufa inqanaba eziphilayo ka ATP iiseli owayo iibhulorho bahlale stably zigxunyekwe olu cingwana actin. Ngoko ke ibakala ngokutyumzayo mortis.

ATP resynthesis

Resynthesis unako ukusebenza ngeendlela ezimbini.

Ngokuthutha enzymatic yeqela phosphate ukusuka creatine phosphate ukuya ADP. Ekubeni noninzi lwezinto creatine esiseleni phi ATP resynthesis iphunyezwe ngokukhawuleza kakhulu. Ngelo xesha, xa igcwala of pyruvic acid kunye lactic acid resynthesis iya kuba kade.

ATP and CP kungaphela ngokupheleleyo ukuba resynthesis yi iityhefu ezaphukileyo. Emva koko ke impompo ikhalsiyam stop yokusebenza, nto leyo imisipha lisenza lifinyele (okt kuza contracture). Ngenxa yoko, kwaphulwa indlela kwemisipha.

inkqubo zomzimba

Ngamafutshane, siphawula ukuba ukuncipha kwimicu izihlunu bufinyeziwe kwi ngasinye myofibrils sarcomeres. Ezi zixhobo ze myosin (zamafu) kunye actin (ezingcakacileyo) iziphelo lidibane sikwimo sikhululekile. Kodwa baqala sliding intshukumo ngayo abanye xa kusetyenziswa indlela imisipha. Physiology (ngokufutshane) ucacisa inkqubo xa myosin nempembelelo uyakhululwa-eneji efunekayo ukuze ukuguqula ATP ku ADP. Ngaloo ndlela umsebenzi myosin iza kuzaliseka kuphela xa isiqulatho elaneleyo ion calcium inokuqokelelana reticulum sarcoplasmic.