Imisipha senhliziyo - izici yokwakheka bokuphila

Imisipha yenhliziyo inikeza imisebenzi ebalulekile kuzo zonke izicubu, amaseli eziyishumi nemitshingo. Ezokuthutha izidakamizwa emzimbeni Kwenziwa ngokusebenzisa njalo kwegazi; Liphinde lunikeze futhi silondoloze homeostasis.

Isakhiwo imisipha yenhliziyo

Inhliziyo imelelwa halves ezimbili - kwesokunxele nakwesokudla, ngamunye esakhiwa Atria futhi ventricles. Uhhafu kwesokunxele inhliziyo iphampa le igazi ophakeme, futhi ilungelo - emithambo yegazi. Ngakho-ke, imisipha yenhliziyo of uhhafu kwesokunxele mkhulu kakhulu kunanoma ilungelo. Imisipha Atria futhi ventricles zihlukaniswe izindandatho fibrous ezithinta valve atrioventricular: ezimbili alo (uhhafu kwesokunxele inhliziyo) kanye tricuspid (isigamu kwesokudla inhliziyo). Lezi valve ngesikhathi ukusikwa inhliziyo ukuvimbela ukubuya igazi Atria. Ngesikhathi ophumayo le-aorta ne-pulmonary Umthambo ezibekwe zonk valve, okuyinto ukuvimbela ukubuya egazi ventricles phakathi inhliziyo diastole Imininingwane.

imisipha senhliziyo kungokwalabo striated kwemisipha izicubu. Ngakho-ke, lokhu imisipha has ezifanayo kodwa ngesikhathi esifanayo njengoba lowo of imisipha lwamathambo. Imisipha fibre siqukethe sarcolemma myofibrillar futhi sarcoplasmic.

Ngenxa inhliziyo ukuletha igazi ngokusebenzisa imithambo yegazi. Ukusikwa komqondo imisipha Atria kanye ventricles (systole) izindlela zokuhamba kanye ukuphumula yayo (diastole). ushintsho Ngokulandelana ka systole futhi diastole lomjikelezo zenhliziyo. Imisipha yenhliziyo isebenza atishaye, esinikezwa ohlelweni, eqhuba ukuyaluza ezingxenyeni ezahlukene inhliziyo

I izakhiwo bokuphila imisipha yenhliziyo

I excitability we myocardium - yikhono layo zisuse ezishukumisa kagesi, mechanical, ezishisayo futhi amakhemikhali. I excitation futhi ukusikwa imisipha yenhliziyo kwenzeka lapho umfutho ifinyelela amandla embundwini. Ngaphansi ukucasuka embundwini akuzona ngempumelelo futhi musa ukushintsha amandla suprathreshold ka ukusikwa esivimba amanzi.

Excitation ijwabu imisipha wenhliziyo ephelezelwa ukubukeka isenzo ezingaba khona. Yena ube mfushane futhi yinde ngesikhathi Ukushaya kwenhliziyo deceleration.

Ejabule senhliziyo esilimele ilahlekelwa kafushane ikhono layo nokusabela ezintweni eyengeziwe noma amaza ivela umthombo automaticity. Lokhu kubizwa ngokuthi refractory non-abangothathekile. ezishukumisa eqinile ukuthi isinyathelo imisipha enkathini refractoriness isihlobo ukubangela i ukusikwa engavamile inhliziyo - okubizwa ngokuthi amabhithi kwesikhathi.

Esivimba amanzi inezici ngokuziqhathanisa lwamathambo kwemisipha izicubu. I excitation nokuncipha ezicutshini inhliziyo isikhathi eside ukwedlula lwamathambo. Ngo imisipha inhliziyo izinqubo aerobic busa resynthesis ocebile compounds. Phakathi diastole, kukhona ushintsho ngokuzenzekelayo bezikhali ulwelwesi kumaseli amaningana ezindaweni ezihlukahlukene isayithi. Ngakho injabulo zibhebhetheka imisipha Atria bufike engeyokuqala atrioventricular, okuyinto kubhekwa maphakathi automaticity II oda. Uma off node sinoatrial (ligated, ukubanda, ubuthi), khona-ke emva kwesikhashana ventricles uqale ungenwa isigqi ngaphezulu ezingavamile bedle amaza ezivela engeyokuqala atrioventricular.

Conduction ka excitation ezingxenyeni ezahlukene inhliziyo ukungalingani. Kufanele sisho ukuthi izilwane ezinegazi elifudumele ngesilinganiso excitation ka atrial imisipha Imicu yotshani imayelana 1.0 m / s; a conductive ventricular uhlelo 4.2 m / s; e myocardium ventricular ukuba 0.9 m / s.

Isici sici excitation we imisipha yenhliziyo ukuthi engaba isinyathelo kubangelwe libe linye kwemisipha izicubu, basakazekela kwezinye amasayithi.