The mashandiro kuti tsandanyama marwadzo. Mashandiro uye zvivako zviri skeletal mhasuro

Muscle marwadzo - muitiro wakaoma kunzwisisa zvinosanganisira vakawanda nzendo. Huru zvinoriumba pano vari myosin, actin, troponin, tropomyosin uye actomyosin, uye calcium yakawanda ions uye yeimwe zvinopa tsandanyama simba. Funga Mhando uye zvigadziriswe kuti tsandanyama marwadzo. Ngationei kudzidza, kubva izvo zvavari aita uye matanho anodiwa kuti cyclical muitiro.

tsandanyama

Tsandanyama ikashandiswa muzvikwata, izvo zvakafanana mashandiro kuti tsandanyama marwadzo. By chete chiratidzo ivo akakamurwa 3 Mhando:

• striated tsandanyama dzomuviri;
• striated tsandanyama of atria uye ventricles mumoyo;
• wakatsetseka tsandanyama nhengo, tsinga uye ganda.

Striated tsandanyama tiri chikamu zvetsandanyama nemapfupa ezvinhu, kuva chikamu chacho, nokuti kunze kwavari, ichi zvinosanganisira nemarunda, nemarunda, mapfupa. Kana pakutevedzera mashandiro kuti tsandanyama marwadzo, kuita zvinotevera mabasa uye mabasa:

• muviri inofamba;
• nhengo dzomuviri vanokurudzirwa hama kune mumwe;
• muviri kunotsigirwa nzvimbo;
• zvinowanisa kupisa;
• cortex iri kusashanda nokuda afferent kuti minda tsandanyama vanogamuchira.

Of kwakanaka mhasuro ndiko:

• gwenya midziyo yacho zvomukati, izvo zvinosanganisira kuti Árbol muti, mapapu uye zvomudumbu chubhu;
• kuti nhengo dzinobudisa uye kweropa nehurongwa;
• maitiro urogenital nhengo.

vasiri ehupfumi

Kufanana vertebrates zvose mumuviri womunhu mune vatatu kukosha ehupfumi ose skeletal mhasuro fibers:

• contractility - kuderedza uye agoshandura voltage kana kuvhundutswa;
• conductivity - kufamba vanokwanisa panyika faibha;
• excitability - kuteerera tide nokuchinja kubva Kamudzira zvinogona uye Ion permeability.

Tsandanyama dziri kufara uye kutanga kuramba ne tsinga nomunhu achibva pakati. Asi pasi chakagadzirwa ezvinhu vachishandisa magetsi dzishande. The tsandanyama inogona zvokugumbukira zvakananga (yakananga dzishande) kana kuburikidza etsinga innervating tsandanyama (kunanga dzishande).

marudzi mavanga

The mashandiro tsandanyama marwadzo zvinoreva kutendeuka kwemakemikari simba kupinda zvokuimba basa. Izvi kuyerwa experimentally pamwe datya: wake mhuru tsandanyama mutoro yakaderera uremu, uye ipapo tsamwisa electroimpulses chiedza. The rutapudzo, umo tsandanyama kunova mupfupi, rinonzi isotonic. kupfupikisa kunoitika apo Isometric marwadzo. Nemarunda hatibvumiri kukura tsandanyama simba mupfupi. Chimwe auksotonichesky mashandiro kuti tsandanyama marwadzo kunosanganisira zvinhu kunetseka kana tsandanyama shortens usingashandi nzira, uye simba kusvika vaifanira.

Marongerwo innervation pamusoro skeletal mhasuro

The striated skeletal tsandanyama rinosanganisira siyana fibers mune connective zvinyama uye wakaiswa kuti nemarunda. Mune dzimwe tsandanyama fibers vanosarudzirwa akaererana refu akabatana, uye vamwe vane oblique maonero, vari kuda munhu nechepakati mudzira tyazhu uye pinnate mhando.

The chikuru chepfungwa faibha riri sarcoplasm vakawanda shinda akanaka - myofibrils. Vane inopenya uye rima dzine rakatumbuka nemumwe, ukuwo pedyo striated fibers vari chomumba - ari pamuchinjikwa-chikamu. Izvi zvinoguma muchinjikwa banding akapoteredza tsandanyama fibers.

Sarcomere chinhu chisinganzwisisiki, rima uye vaviri chiedza disks, uye delimited Z-zvakaumbwa mitsetse. Sarcomeres - a contractile midziyo ine tsandanyama. Zvakaratidza kuti contractile tsandanyama faibha chinosanganisira:

• contractile midziyo (myofibrils maitiro);
• trophic midziyo pamwe mitochondria, Golgi yakaoma uye simba endoplasmic reticulum ;
• ari Kamudzira mudziyo;
• bhuku midziyo;
• huta midziyo.

Muscle faibha rakakamurwa 5 nhengo pamwe zvivako zvavo uye mashandiro, uye chinhu chinokosha pamusoro tsandanyama tishu.

innervation

Izvi zviri striated tsandanyama fibers vakaziva kubudikidza tsinga fibers, kureva axons pakati injini Tutsinga tunofambisa mashoko utwu pamusoro musana uye pfungwa hunde. Mumwe motoneuron innervate wandei tsandanyama fibers. Complex ane motoneuron uye innervated tsandanyama fibers anonzi neuromotor (HME) kana injini chikwata (CA). Average uwandu fibers, iyo innervates munhu motoneuron, kuratidza DE tsandanyama, rinonzi itirana innervation arambe achirema. Yokupedzisira ndiyo pakukura tsandanyama, apo diki kufamba uye "dzakaonda" (maziso, minwe, rurimi). Its ukoshi muduku, nekusiyana, iri tsandanyama ane "zvinonyadzisa" inofamba (semuenzaniso, mutumbi).

Innervation inogona kuroorwa uye vakawanda. Muchiitiko chokutanga riri akaziva tsindirana motokari harinzwi. Kazhinji ndizvo kuti hombe motokari Tutsinga tunofambisa mashoko utwu. Muscle fibers (akadana iyi, mumuviri, kana kutsanya) generating PD (chiito potentials) kuti anoshanda kwavari.

Multiple innervation kunoitika Somuenzaniso, muna kwokunze ziso netsandanyama. Izvi hazvina chiito vangangova iri vanowanika, sezvo Kamudzira hapana electroexcitability yavaibvisa makwara. Vari richiparadzirwa munyika internet depolarization ari synaptic harinzwi. Izvi zvinokosha kuti Activate kuti mashandiro kuti tsandanyama marwadzo. Masero pano hakusi kutsanya sezvo mumutsetse wokutanga. Saka, inonzi kunonoka.

The nemamiriro myofibrils

tsandanyama internet tsvakurudzo kuitwa nhasi pahwaro X-ray diffraction, Erekitironi microscopy, uye histochemical nzira.

It rinowanikwa kuti mune mumwe myofibril, ari dhayamita izvo zviri 1 micron, kunosanganisira inenge 2,500 protofibrils, i.e. elongated polymerized mamorekuru mapuroteni (actin uye myosin). Actin protofibrils kaviri wakawondereiko kudai mazuva ose myosin. Panguva yokuzorora, tsandanyama idzi dziri kuti actin filament yokutenda kupinda munzvimbo magwanza pakati myosin protofibrils.

A nepaburi kanyika chiedza muna dhisiki A akasununguka kubva actin filaments. A Kamudzira Z akabata pamwe.

On the myosin filaments vane lateral miganhu anosvika 20 nm, musoro uri myosin mamorekuru anenge 150. Vaende biopolyarno, uye mumwe musoro myosinic rinobatanidza kuti actin filament. Kana pane kunetseka pamusoro filaments pakati actin nzvimbo myosin, actin filament riri pedyo nepakati sarcomere. Panoperera ari myosin filaments kusvika mutsetse Z. Vakabva kutora sarcomere wose, uye actin zviri pakati pavo. Panguva iyoyo ndodzinga urefu ipfupi, uye pakupedzisira anonyangarika zvachose, pamwe zvinoreva mutsetse Z kunova mukobvu.

Saka, maererano dzidziso kutamira pemavara, nokuda akaderedza Kureba tsandanyama fibers. Fungidziro, inonzi "giya", akanga yakataurwa Huxley uye Hanson pakati pezana remakore rechimakumi maviri.

Mashandiro kuti tsandanyama internet marwadzo

The chikuru dzidziso iri kuti hapana filament (myosin uye actin) vari mupfupi. kureba yavo inoramba kuzochinja uye tsandanyama kukakavadzana. Asi vanomirirwa nemwanda matete filaments, rwotedzemuka, enda pakati makobvu filaments, zvinoderedza ukuru bindepinde, saka pane rutapudzo.

The samolecular mashandiro tsandanyama marwadzo ari sezvinotevera pedyo zvishoma nezvishoma mumatope actin filaments. Myosin musoro kwakabatana protofibrils pamwe actin. With dzakatenuka dzavo pane zviri zvishoma nezvishoma mumatope, kufambisa actin filament kusvika nepakati sarcomere. Nokuda nedambudziko sangano myosin mamorekuru kumativi ose filaments, zvinhu nokuti zvishoma nezvishoma mumatope enyika actin filaments kwakasiyana-siyana.

Kana tsandanyama kutandara myosin musoro runoita kubva actin filaments. With nyore pitikoti vagadzikana tsandanyama makakatanwa tichidzivisa shoma zvikuru. Saka, vari tinyerere miforo.

rutapudzo matanho

The mashandiro tsandanyama marwadzo chinogona zvishoma akakamurwa anotevera matanho:

1. Muscle faibha dzinovhurika kana chiito zvinogona iri kusvitsa kubva injini Tutsinga tunofambisa mashoko utwu ari synapses.
2. The chiito zvinogona iri vanowanika pamusoro Kamudzira ari tsandanyama faibha, uye ipapo anopararira kusvika myofibrils.
3. Chakazadziswa electromechanical peya inomirira kutendeutsa zvemagetsi kupinda zvemaziso zvishoma nezvishoma mumatope PD. Izvi hazvo kunosanganisira zvokudya zvine calcium ions.

karusiyamu ions

Nokuti kunzwisisa nedanho internet activation calcium ions nani zviri nyore kufunga nemamiriro actin filament. Kureba woda 1 m, ukobvu - kubva 5 kusvika 7 nm. Ichi peya yakakoswa neshinda, izvo vakafanana actin monomer. Inenge ose 40 nm pano vari idenderedzwa troponin Morekuru, uye pakati ngetani - tropomiozinovye.

Kana karusiyamu ions hatisi, kureva myofibrils usanetseka refu tropomiozinovye mamorekuru adzikatidza kuda kuti actin ngetani uye myosin mabhiriji. Asi kana kusashanda karusiyamu ions tropomiozinovye mamorekuru kunyura zvakadzama uye akazaruka munzvimbo.

Ipapo myosin mabhiriji vari kuda actin filaments uye ATP rinotsemuka uye anovandudza tsandanyama simba. Izvi zvinogoneka nokuda kwechirwere calcium troponin. In Morekuru iyi yokupedzisira ari akaremara, nokudaro kukuvadza tropomyosin.

Kana tsandanyama akadekara, ndiko 1 giremu nyoro uremu ine anopfuura 1 mmol calcium. Karusiyamu munyu muri kure uye chinokosha okuchengetera zvivako. Zvikasadaro, tsandanyama kuti nguva dzose kutsauka.

karusiyamu iiswe sezvinotevera. In siyana nzvimbo diaphragm tsandanyama masero mukati faibha sepombi kuburikidza ine chokuita nharaunda kunze masero. Zviri kwegadziriro transverse tubules. A kwava perpendicular kusvika longitudinal kumigumo iyo - vesicles (chinouraya) Matangi vanosarudzirwa pedyo napedyo kusvika transverse diaphragms hurongwa. Pamwe kuwana vanamwari vatatu vatatu. Yakanga iri ndiro zvakachengetwa karusiyamu.

Sezvo PD ari kuparadzirwa munzvimbo muchitokisi, uye pane electromechanical conjugation. Excitation chinopinda ari faibha zvinoenda munhu longitudinal hurongwa zvabudiswa karusiyamu. Saka rutapudzo mashandiro chiitwe tsandanyama fibers.

3 urongwa pamwe ATP

In kubata zvose tambo pamberi calcium ions rebei basa nokuda ATP. Kana pakutevedzera mashandiro ose tsandanyama marwadzo ose skeletal tsandanyama, nesimba ATP rinoshandiswa:

• nokushanda yavaibvisa uye potassium pombi iyo anoramba kuramba Kuwanda ions;
• zvinhu izvi kumativi akasiyana pamusoro Kamudzira;
• zvishoma nezvishoma mumatope filaments vachigurisira myofibrils;
• Job karusiyamu pombi kuita kuzorora.

ATP ndiye muchitokisi Kamudzira, ivo filaments ose myosin uye sarcoplasmic reticulum membranes. Makemikari yokuputsa kuraswa myosin.

kudyiwa ATP

Zvinozivikanwa kuti myosin misoro nekutaurirana ne actin uye rine zvinhu nokuda ATP cleavage. Last kusashanda actin uye myosin pamberi magnesium ions. Naizvozvo enzayemu cleavage kunoitika apo kuda actin myosin musoro. The chikuru muchinjikwa mabhiriji, kukamurwa nokukurumidza uchava kwirirei.

ATP mashandiro

Pashure pokupedza kwebasa AFL Morekuru rinoita simba nekuti akazvitsaurira maitiro mukupara actin uye myosin. Myosin musoro vakaparadzana, ATP ari dzainamatira phosphate uye ADP. Panopera rinobatanidza itsva ATP Morekuru uye kutenderera Tinoenderera mberi. Ndizvo mashandiro kuti tsandanyama marwadzo uye kutandara panguva samolecular chechetere.

Basa muchinjikwa mabhiriji kuchapedza chete sokuvapo ATP hydrolysis kunoitika. Kana iwe adzikatidza enzayemu mabhiriji Haingaropafadzwi zvakabatanidzwa zvakare.

Pakatanga rufu nhengo pamwero ATP ari mumasero rinowira uye mabhiriji kuramba stably wakaiswa kuti actin filament. Saka pane padariro nehasha mortis.

ATP resynthesis

Resynthesis anogona chinozoiswa nenzira mbiri.

By enzymatic kuchinjwa phosphate boka kubva creatine phosphate kuna ADP. Sezvo mumatanda ose creatine muchitokisi yakawanda ATP resynthesis chinozoiswa nokukurumidza chaizvo. Panguva iyoyowo, kubudikidza oxidation pamusoro pyruvic asidhi uye lactic iine acid resynthesis achava kunonoka.

ATP uye CP anogona kunyangarika zvachose kana resynthesis runovhuniwa chepfu. Ipapo karusiyamu pombi chemabhazi vanoshanda, zvichiguma tsandanyama ipfupi irreversibly (kureva kuuya contracture). Saka, kuputswa mashandiro tsandanyama marwadzo.

physiology urongwa

Mukupfupikisa, tinoona kuti rutapudzo kuti tsandanyama fibers iri pfupi mumwe nomumwe myofibrils sarcomeres. The filaments pamusoro myosin (gobvu) uye actin (mutete) kwakabatana kumagumo vari wakasununguka ezvinhu. Asi havana kutanga zvishoma nezvishoma mumatope vade mumwe kana chinozoiswa mashandiro ose mhasuro marwadzo. Physiology (zvishoma) rinotsanangura kana kukanganiswa myosin ukasunungurwa simba rinodiwa kuti exchange ATP kuna ADP. Saka myosin basa chichazadzika chete kana munhu anogutsikana calcium ions zvakakwana uchingounganidza ari sarcoplasmic reticulum.