Ngenkinga yokucindezeleka yesikhashana, isibonelo, uma sizama ukubamba ibhasi, umzimba uyakwazi ukuhlinzeka ngokushesha amandla okwandisa imisipha. Lokhu kungenzeka ngenxa yokutholakala kwamakhemikhali e-oxygen, kanye nokuphendula kwama-anaerobic (ukukhiqizwa kwamandla ngokungabikho kwe-oxygen). Isidingo samandla sanda kakhulu ngokusebenza komzimba okwesikhathi eside. Imisipha idinga oksijeni okwanele ukuhlinzeka nge-aerobic (ukukhiqizwa kwamandla okubandakanya oksijeni). Izindinganiso zansuku zonke zomsebenzi womzimba: ziyini?
Umsebenzi we-cardiac
Inhliziyo yomuntu ekuphumule incishiswe ngevolumu yezinsimbi ezingaba ngu-70-80 ngomzuzu. Ngomsebenzi womzimba, imvamisa (kuze kube yizingoma ezingu-160 ngomzuzu) futhi amandla okwanda kwenhliziyo ayanda. Ngesikhathi esifanayo ukujula kwenhliziyo kumuntu onempilo kungakhula okungaphezu kwesine, kanye nabagijimi abaqeqeshwe - cishe izikhathi eziyisithupha.
Umsebenzi we-Vascular
Ngesikhathi sokuphumula, igazi liphonswa yinhliziyo ngesilinganiso cishe amalitha angu-5 ngomzuzu. Ngomsebenzi womzimba, ijubane lenyukela ku-25-30 amalitha ngomzuzu. Ukwanda kwegazi kuqhutshwa ikakhulukazi emisipha yokusebenza, edingeka kakhulu kuwo. Lokhu kutholakala ngokunciphisa ukunikezelwa kwegazi kwalezo zindawo ezingasebenzi kakhulu ngaleso sikhathi, nangokukhulisa imithwalo yegazi, okuhlinzeka ukugeleza okukhulu kwegazi emisipha esebenza.
Umsebenzi wokuphefumula
Ukujikeleza igazi kufanele kube ne-oxygenated ngokwanele (oksijini), ngakho-ke izinga lokuphefumula liyanda. Kulesi simo, amaphaphu angcono kakhulu agcwaliswe oksijeni, okuyinto engena egazini. Ngokuzikhandla ngokomzimba, izinga lomoya lokungena emaphashini landa lifika ku-100 amalitha ngomzuzu. Lokhu kungaphezu kokuphumula (6 amalitha ngomzuzu).
• Inani lomkhiqizo wenhliziyo emgijimeni we-marathon lingaba ngaphezulu kuka-40% kunomuntu ongafundile. Ukuqeqeshwa njalo kukhulisa ubukhulu benhliziyo nomthamo wezinsika zawo. Ngesikhathi sokusebenza ngokomzimba, izinga lokushaya kwenhliziyo (inani lemivimbo ngeminithi) nokukhishwa kwenhliziyo (ivolumu yegazi ekhishwa yinhliziyo eminithi elingu-1) ukwanda. Lokhu kungenxa yokuvuselela kwemizwa, okwenza inhliziyo isebenze kanzima.
Ukubuya okubuhlungu okubuhlungu
Ivolumu yegazi ebuyela enhliziyweni ithuthukiswa yi:
• Ukunciphisa ukumelana kwamagciwane emisipha ngenxa ye-vasodilation;
• Ucwaningo oluningi luye lwaqhutshwa ukutadisha izinguquko ohlelweni lokujikeleza ngesikhathi sokuzivocavoca. Kwafakazelwa ukuthi zilingana ngokuqondile nokusebenza komzimba.
- umsebenzi wemisipha (ukunciphisa nokuphumula);
• ukunyakaza kwesifuba ngokuphefumula okusheshayo, okubangela umphumela "wokulwela";
• Ukunciphisa imithanjeni, okusheshisa ukuhamba kwegazi emuva enhliziyweni. Lapho ama-ventricles enhliziyo egcwele igazi, izindonga zalo ziyanweba futhi zivumelaniswe ngamandla amakhulu. Ngakho-ke, inhliziyo ilahla ivolumu ekhuphuka yegazi.
Ngesikhathi sokuqeqeshwa, ukugeleza kwegazi kumisipha kwanda. Lokhu kuqinisekisa ukulethwa kwesikhathi okwamanje kwe-oxygen nezinye izakhi ezidingekayo kubo. Ngisho nangaphambi kokuba imisipha iqale ukuvumelanisa, ukugeleza kwegazi kuzo kuthuthukiswa yizimpawu ezivela ebuchosheni.
Ukwandiswa kwe-Vascular
Izimo ezikhathazayo zesimiso sezinzwa ezizwelayo zibangelwa ukuhlanjululwa (ukukhuliswa) kwezinto ezisebusweni, okwenza ivolumu ekhudlwana yegazi iphele emangqamuzaneni emisipha. Kodwa-ke, ukuze kugcinwe izitsha endaweni ehlanjululwe ngemuva kokuxilongwa okuyisisekelo, izinguquko zendawo ezithinta izicubu - ukwehla ezingeni le-oksijeni, ukwanda kwezinga le-carbon dioxide kanye neminye imikhiqizo yemethamo eyenziwe ngenxa yezinqubo zezinto eziphilayo ezinomzimba wesisipha. Ukwanda kwendawo ekushiseni okubangelwa ukukhiqizwa okushisa okwedlulele nokuqhekeka kwemisipha nakho kunomthelela ekwenzeni i-vasodilation.
I-Vascular narrowing
Ngaphandle kwezinguquko ngqo emisipha, igazi eligcwalisa ezinye izicubu nezitho zinciphisa, okuyinto isidingo esincane sokwandisa amandla ngesikhathi sokusebenza ngokomzimba. Kulezi zindawo, ngokwesibonelo, emathunjini, ukunciphisa imithwalo yegazi kubonakala. Lokhu kuholela ekusatshaneni kwegazi kulezo zindawo lapho kuyadingeka kakhulu, ukuhlinzeka ngegazi okwandiswayo kumisipha emjikelezweni olandelayo wegazi. Ngomsebenzi womzimba, umzimba udla oksijini okwedlula ukwedlula ukuphumula. Ngenxa yalokho, uhlelo lokuphefumula kumele luphendule isidingo sokwanda kwe-oksijeni ngokwandisa umoya. Ukuvame ukuphefumula ngesikhathi sokuqeqeshwa kwanda ngokushesha, kodwa indlela ecacile yokusabela okunjalo ayiyazi. Ukwandiswa kokusetshenziswa kwe-oksijeni nokukhiqizwa kwe-carbon dioxide kubangela ukucasuka kwama-receptors okuthola izinguquko ekubunjweni kwegazi, okuholela ekuvuseleleni ukuphefumula. Kodwa-ke, ukusabela komzimba ekucindezelekeni ngokomzimba kuphawulwa kakhulu ngaphambi kokuthi izinguquko ezakhiweni zamakhemikhali zegazi zizorekhodwa. Lokhu kubonisa ukuthi kunezinqubo ezisekelwe impendulo ezithumela isignali emaphashini ekuqaleni kokusebenza komzimba, ngaleyo ndlela ukwandisa izinga lokuphefumula.
Amamukeli
Abanye ochwepheshe basikisela ukuthi ukwanda kancane kwezinga lokushisa, okubonakalayo, ngokushesha nje lapho imisipha iqala ukusebenza, ivuselela ukuphefumula kaningi futhi okujulile. Kodwa-ke, izindlela zokulawula ezisisiza ukuba siqhathanise izici zokuphefumula nesilinganiso se-oksijeni edingekayo yimisipha yethu inikezwa ngamamukeli amakhemikhali atholakala ebuchosheni nasemiphakathini emikhulu. Ukuze kusetshenziswe ukushisa nokusebenza ngokomzimba, umzimba usebenzisa izindlela ezifanayo nalabo abasungulwa ngosuku olushisayo ukuze lupholile, okungukuthi:
• Ukwandiswa kwezikebhe zesikhumba - ukwandisa ukudluliselwa kokushisa kwimvelo yangaphandle;
• ukukhukhuma okukhukhulayo - ukujuluka kuphuphuma endaweni yesikhumba, okudinga izindleko zamandla ashushu;
• Ukunyuka kwamapayipi okwandisa - ukushisa kukhishwa ngomoya wokufudumala.
Ukusetshenziswa kwe-oksijeni ngomzimba kwabagijimi kungenziwa ukwandiswa izikhathi ezingu-20, futhi inani lokushisa elikhishwe cishe lilingana ngqo nokusetshenziswa kwe-oxygen. Uma ukuthuthumela ngosuku olushisayo nolumanzi alwanele ukupholisa umzimba, isimo esiphuthumayo esingokomzimba singabangela isimo esisongela ukuphila esibizwa ngokuthi ukushaywa kwesibindi. Ezimweni ezinjalo, usizo lokuqala kumele kube ngokushesha uma kunokwenzeka ukwehliswa kokufakelwa kokushisa komzimba. Umzimba usebenzisa izindlela ezihlukahlukene zokuzipholisa ngokwengqondo ngesikhathi sokusebenza komzimba. Ukwanda kwe-sweating kanye ne-pulmonary ventilation kusiza ukwandisa ukukhishwa komshini.