Maumbirwo uye Basa reMyocardium
Myocardium, kana kuti tsandanyama yemwoyo, chinhu chakakosha muhurongwa hwemwoyo hwevanhu. Basa rayo guru nderekupomba ropa mumuviri wese, basa rinoda kushanda nesimba uye kutsungirira, tichifunga kuti mwoyo unoshanda usingamiri muhupenyu hwese hwemunhu. Kuti unzwisise kuoma kwayo, kudzidza nezvemaumbirwo ayo nebasa rayo kwakakosha. Chinyorwa chino chichakurukura nezvemaumbirwo ayo, chimiro chemasero, uye histology yemyocardium, pamwe chete nemabasa ekutanga uye physiology yakaoma yetsandanyama iyi yemwoyo.
Kuumbwa uye Maumbirwo eMyocardium
Mwoyo une zvikamu zvitatu zvikuru: endocardium (chikamu chemukati), myocardium (chikamu chepakati, icho chatinotarisisa), uye epicardium (chikamu chekunze). Myocardium ichikamu chakakora chinotongwa nefibers dzemhasuru dzemwoyo, kana kuti cardiomyocytes.
Myocytes
Cardiomyocytes rudzi rwakasiyana rwemasero emhasuru ane zvinhu zvakasiyana zvinovabvumira kushanda zvakanaka uye nguva dzose pasina kuneta. Zvimwe zvezviratidzo zvinosiyanisa cardiomyocytes zvinosanganisira:
1. Kureba kwemasero nebazi: Masero aya ane chimiro chakareba uye chine matavi, zvichiabvumira kubatana mu network yakaoma.
2. Nucleus imwe chete kana mbiri: Kazhinji dzine nuclei imwe kana mbiri pasero rega rega.
3. Madhisiki epakati pekarori: Maumbirwo aya anobvumira kubatana kwakasimba pakati pemasero pamwe nekukurumidzira kutamiswa kwema electric impulses, izvo zvakakosha pakubatanidza marwadzo emwoyo.
4. Mitochondria yakawanda: Inobvumira kugadzirwa kweATP zvakanaka kutsigira basa rinoenderera mberi rekudzikira kwemasero.
Madhisiki eIntercalary uye Gap Junctions
Madhisiki akasanganiswa maumbirwo akakosha anowanikwa mumasero emhasuru dzemwoyo chete. Anosanganisira:
1. Desmosomes: Zvimiro zvinobatanidza masero nenzira yemakanika, zvichipa simba nekugadzikana.
2. Kubatana kweMagedhi: Kunopa nzira yekufambisa maion nemamorekuru madiki pakati pema cardiomyocytes, zvichibvumira masaini emagetsi kupararira nekukurumidza uye zvichiita kuti tsandanyama yemwoyo ibatane.
Kugadziriswa kweropa remwoyo
Myocardium ine ropa rakakwana kuburikidza netsinga dzemwoyo. Iyi network yemoyo inoita kuti cardiomyocytes iwane okisijeni yakakwana uye zvinovaka muviri kuti zvitsigire kushanda kwavo nguva dzose. Kukanganiswa kwekuyerera kweropa mumoyo, senge mukurwara nemoyo (myocardial infarction), kunogona kukonzera kukuvara kwakanyanya kwemoyo.
Basa reMyocardium
Basa guru remyocardium nderekusungana, izvo zvinoita kuti mwoyo ukwanise kupomba ropa. Basa iri rinoitwa kuburikidza nematanho akasiyana-siyana uye zvikamu zvemuviri uye zvemakemikari.
Kudzikama uye Kuzorodzwa
Maitiro ekurwadziwa kwemoyo anozivikanwa sesystole, nepo maitiro ekuzorora achizivikanwa sediastole. Munguva yesystole, ma cardiomyocytes anogumira uye anodzvinya ropa kubva mumakamuri emwoyo. Zvadaro, panguva yediastole, anozorora uye anobvumira makamuri kuzadza neropa.
Maitiro eMolecular eKubata
Kubatana kwemwoyo nemyocyte kunosanganisira kusangana pakati pemapuroteni e actin ne myosin mu sarcomere, chikamu chidiki chetsandanyama. Matanho makuru anobatanidzwa ndeaya anotevera:
1. Kubviswa kwepolarization yeMembrane: Kubviswa kwepolarization yemagetsi kunokonzerwa ne sinoatrial node (SA node) kunopararira kuburikidza nemukati memoyo, zvichikonzera kubviswa kwepolarization ye cardiomyocyte membrane.
2. Kuvhurwa kweCalcium Channels: Kubviswa kwepolarization uku kunokonzera kuvhurwa kweL-type calcium channels mu cell membrane, zvichibvumira kufamba kwema calcium ions mu cell.
3. Kuburitswa kweCalcium kubva kuSarcoplasmic Reticulum: Maion ecalcium anouya anokonzera kuburitswa kwecalcium yakawedzerwa kubva kusarcoplasmic reticulum, zvichiwedzera huwandu hwecalcium mumasero.
4. Kubatana kweCalcium neTroponin: Calcium inosungana neprotein yetroponin, zvichikonzera shanduko inovhura nzvimbo yekubatanidza myosin paactin.
5. Kufamba kweActin neMyosin Sweep: Kana nzvimbo idzi dzekusunga dzavhurwa, misoro yemyosin inogona kusungirana neactin uye kushandisa ATP kugadzira kusungwa ne "power stroke".
Mutemo weFiziki
Myocardium haishande yoga; basa rayo rinodzorwa zvakanyanya nenzira dzakasiyana-siyana:
1. Autonomic Nervous System: Sisitimu dzetsinga dzinonzwira tsitsi uye dzinoparara dzinokanganisa zvakananga kurova kwemoyo uye simba rekurwadziwa kwemoyo.
2. Mahormone: Mahormone akadai se epinephrine anogona kuwedzera kuwanda uye simba rekurwadziwa kwemoyo.
Mabasa eCircadian Drive uye Metabolic
Kusagadzikana kwepfungwa nechirwere chemwoyo zvinowanzoitika kakawanda panguva dzakati wandei dzezuva, zvichiratidza kuti mwoyo une simba pakushanda kwemoyo. Masero emwoyo anofanirawo kuchengetedza kuenzana kwemetabolism pakati pekushandiswa kwemacarbohydrates nemafuta acids senzvimbo dzinopa simba.
Pathology yeMyocardial
Zvirwere zvinokanganisa myocardium zvinogona kukanganisa mashandiro ayo uye kukonzera matambudziko akasiyana-siyana ehutano. Zvimwe zvezvirwere zvinowanzoonekwa zvinosanganisira:
Kufa kwemwoyo
Kurwara kwemwoyo, kunozivikanwa sechirwere chemwoyo, kunoitika kana ropa richienda kuchikamu chemoyo rikabva rangoerekana ramira, kazhinji nekuda kwekuumbwa kweatherosclerotic plaque kana kuti ropa rakagwamba mutsinga dzemwoyo. Pasina okisijeni yakakwana, nyama yemoyo inofa yorasikirwa nebasa rayo.
Cardiomyopathy
Cardiomyopathy izwi rinowanzo shandiswa kureva chirwere chemwoyo chinoita kuti tsandanyama dzemwoyo dzikure, dziome, kana kuti dzikobvu, zvichiita kuti dzisakwanise kupomba ropa. Kune mhando dzakasiyana-siyana, dzinosanganisira dilated cardiomyopathy, hypertrophic cardiomyopathy, uye restrictive cardiomyopathy.
Kukundikana kwemoyo
Kukundikana kwemoyo chirwere chinokonzerwa nekuti mwoyo haugone kupomba ropa rakakwana kuti muviri ukwanise kugutsa zvinodiwa nemoyo. Izvi zvinokonzerwa nezvirwere zvakasiyana-siyana zvemwoyo zvinokanganisa kana kuderedza simba remwoyo.
Arrhythmia
Kusagadzikana kwemoyo, kana kuti arrhythmias, kunogona kuitika kana zviratidzo zvemagetsi zvinodzora marwadzo emwoyo zvikasava nemaitiro akafanana. Arrhythmias inogona kubva pakuva isina njodzi kusvika pakuva nehupenyu hune njodzi uye inogona kuitika nekuda kwezvikonzero zvakasiyana-siyana, kusanganisira kukuvara kwemyocardium.
Myocarditis
Myocarditis kuzvimba kwetsandanyama yemwoyo kunogona kukonzerwa nehutachiona, mabhakitiriya, kana kutoita autoimmune reaction. Chirwere ichi chinogona kukanganisa cardiomyocytes uye kukanganisa mashandiro emoyo.
Mhedziso
Myocardium imhasuru dzemwoyo, nhumbu ine basa guru mukupomba ropa mumuviri wese. Kunzwisisa maumbirwo uye mashandiro emyocardium, kubva kumasero kusvika kuhurongwa hwemuviri, kwakakosha pakunzwisisa hutano hwemwoyo nezvirwere. Kunzwisisa uku kunobvumira kudzivirira, kuongororwa, uye kurapwa kwezvirwere zvinokanganisa tsandanyama dzemwoyo zvinobudirira, zvichiita kuti kudzidza myocardium kuve nzvimbo yakakosha yekuongorora mwoyo.
