Imijikelezo yokujikeleza kwegazi emzimbeni womntu

Amalungu egazini legazi emzimbeni womntu avumela igazi ukuba lenze yonke imisebenzi efunekayo. Ingundoqo yokujikeleza ngegazi kukuhamba kwegazi ngeempahla ukuze kuqinisekiswe izinto eziyimfuneko kuzo zonke izitho zomntu. Inkqubo yonke yenkqubo yokujikeleza iqulethwe yimithambo yegazi kunye nentliziyo. Ngenxa yokuqhekeka kwentliziyo yesisu, igazi liqhutyelwa kwiinqanawa. Kukho iintlobo ezimbini zeenqanawa: iirriyiti (ithwala igazi ukusuka kwintliziyo yentloko ukuya kwizitho kunye nezicubu) kunye nemithanjeni, apho igazi lihamba khona entliziyweni. Phakathi kwazo zonke iinqanawa zidibaniswe ne-capillaries encinci yegazi.
Izijikelezo ezilandelayo zijikeleza kumntu : omncinane, omkhulu. Isiqu okanye isangqa esikhulu sivela kwi-ventricle yekhohlo yentliziyo. Emva koko igazi ligeleza kwi-artery ephambili emzimbeni womntu - i-aorta. Ukususela kwi-aorta, igazi liye lasasaza emlanjeni, ngenxa yemibhobho encinci. Xa sele ifikelele kumalungu, iirribhethi zahlulwa zibe yi-arterioles, iinqanawa ezincinci, eziye zahlula zibe ngama-capillari. Ngoko izitho kunye nezicubu zigcwele i-oxygen kunye nezondlo eziyimfuneko ekusebenzeni ngokuqhelekileyo komzimba. Ngokufanayo, ukuqala kwi-capillaries, igazi eliyingqumbo lingena emithanjeni emikhulu yomzimba, ephantsi nangaphezulu. Emva koko ihanjiswa kwi-atrium efanelekileyo. Umjikelezo wonke umjikelezo omkhulu wegazi.
I-pulmonary, okanye enye ingqungquthela encinane, ifaka indlela emfutshane. Ukusuka kwi-ventricle efanelekileyo yentliziyo ishiya i-artery enkulu, eyahlukana ibe yimibhobho emibili yepommoni. Ngoko igazi elithanjiswa ngomoya-mpilo linikezelwa kwimiphunga. Iimitha zeentlobo ezinkulu zihlukaniswe zibe yi-arterioles, kwaye ezo, ngokwazo, zahlula zibe ngama-capillari. Yiyo leyo eyenza ikwazi ukuzalisa imiphunga nge-oksijini kwaye ihlambulule i- carbon dioxide. Oku kukutshintshiselwa kwamagesi emiphakeni. Emva koko igazi legazi liphuma phakathi kweemvini ukuya kwi-atrium ekhohlo.
Imijikelezo emancinci kunye neyona enkulu yokujikeleza kwegazi inemisebenzi efana nayo yazo zonke izitho. Iimitha zegazi zihambisa igazi, zigcwele izakhi kunye ne-oksijeni, kwizitho kunye nasezikhunjini. Iimvumba, kwakhona, zibuyisela igazi eliphambeneyo entliziyweni. Umehluko kuphela umgama: omkhulu kunye ncinane. Imijikelezo yokujikeleza kwegazi yenza umsebenzi wokuzaliswa kweeseli zomzimba nge-oxygen.
Kodwa ukujikeleza kwimijikelezo ayigudluli lonke igazi elisemzimbeni. Amanye igazi agcinwa kwiindawo zokugcina igazi. Zisepeni, isibindi, imiphunga kunye neqoqo leempahla phantsi kwesikhumba. Ezi zindawo ezifunekayo zongxamiseko lweengxaki kunye nezicubu ezineoksijini.
Ukuhanjiswa kwegazi phakathi kwamalungu omzimba ngamnye akufanelanga. Imijikelezo yegazi ihambisa igazi, kuxhomekeke kwimisebenzi yelungu okanye izicubu. Oku kwenzeka njengoko izitya ziyakwandisa kwaye zenze isivumelwano. Igazi kwiqumrhu elisebenzayo lisebenza kwixabiso elikhulu ngenxa yokuhamba kwegazi ngaphantsi kwamanye amalungu, angasebenzi phantsi.
Imijikelezo yomsebenzi wokujikeleza ngegazi ngenxa yenkqubo yeemithana yegazi, kwaye kunjalo, i-heart muscle. Iimitha ze-arteries zithatha ukuhanjiswa kwezitho kunye nezicubu zegazi ezichithwe nge-oksijini kunye nezixhobo zondlo. Siyabonga kubo, uxinzelelo lwegazi oluphezulu lugcinwa, kuqinisekiswe ukuhamba kwegazi ngokukhawuleza kwi-capillaries kunye nokuzaliswa kwezicubu kunye namalungu.

Igazi eliye ladlulela kwijikelezo zomjikelezo, iqulethe iimveliso zomsebenzi obalulekileyo womzimba womntu kunye necarbon dioxide. Igazi elinjalo lithwala iinqanawa, ezibizwa ngokuba yimifuno.
Ama-Capillaries nawo adlala indima ebalulekileyo kwinkqubo yonke yokujikeleza. Le nethiwekhi yenqwelwana yeenqanawa ezincinci, apho igazi, eligcwele izondlo kunye ne-oksijeni, lihamba ngqo kwiimisipha kunye nezicubu zeenxalenye.
Inkqubo yonke yokujikeleza ibaluleke kakhulu ebomini bomzimba. Intliziyo, imithwalo yegazi kunye nokusasazwa yizona zinto ziyinxalenye.