Umehluko Phakathi Kwegazi Lemithambo Negazi Lemithambo
Esimiso sokujikeleza kwegazi somuntu, imithambo yegazi nemithambo yegazi kuyizinhlobo ezimbili eziyinhloko zemithambo yegazi ezidlala indima ebalulekile. Zisebenza ndawonye ukuqinisekisa ukuthi wonke amaseli emzimbeni athola umoya-mpilo nezakhamzimba, kuyilapho futhi zisiza ekususeni imfucuza ye-metabolic efana ne-carbon dioxide. Kodwa-ke, yize zombili zithwala igazi, imithambo yegazi nemithambo yegazi inomehluko oyisisekelo maqondana nokugeleza kwegazi, okuqukethwe umoya-mpilo, isakhiwo sodonga lwemithambo yegazi, umfutho wegazi, kanye nomsebenzi wazo ekugcineni ukuzinza komzimba. Lesi sihloko sixoxa ngomehluko phakathi kwegazi lemithambo yegazi nelemithambo yegazi ngokucacile nangokuphelele.
Ukuqonda igazi elisemithanjeni yegazi kanye negazi elisemithanjeni yegazi
Ngokuvamile, igama elithi "igazi lemithambo yegazi" libhekisela egazini eligeleza emithanjeni yegazi, kanti elithi "igazi lemithambo yegazi" libhekisela egazini eligeleza emithanjeni yegazi. Kodwa-ke, igama elithi "igazi lemithambo yegazi" livame ukuhlotshaniswa negazi elinomoya-mpilo omningi, kanye nelithi "igazi lemithambo yegazi" negazi elingenawo umoya-mpilo. Lokhu kuhlangana ngokuvamile kuyiqiniso ekujikelezeni kwegazi okujwayelekile (ukujikeleza kwegazi okukhulu), kodwa kukhona okuhlukile okubalulekile ekujikelezeni kwegazi kwamaphaphu (ukujikeleza kwegazi okuncane), okuzochazwa kamuva.
Isiqondiso sokugeleza: kusukela enhliziyweni uma kuqhathaniswa nokuya enhliziyweni
Umehluko oyisisekelo phakathi kwemithambo yegazi nemithambo yegazi yindlela igazi eligeleza ngayo:
– Imithambo yegazi ithwala igazi lisuka enhliziyweni liye ezicutshini noma ezithweni zomzimba.
– Imithambo yegazi ithwala igazi libuyele enhliziyweni ngemva kokuba igazi “selisetshenziswe” yizicubu.
Ngamanye amazwi, imithambo yegazi “iyizindlela zokusabalalisa,” kanti imithambo yegazi “iyizindlela zokubuyela emuva.” Le ndlela yokugeleza kwegazi ihlala ifana, yize okuqukethwe komoya-mpilo kungahluka ekujikelezeni kwegazi okuthile.
Okuqukethwe kwe-oksijini kanye ne-carbon dioxide
Ekujikelezeni kwegazi okujwayelekile, okuqukethwe yigesi egazini lemithambo yegazi kanye nelemithambo yegazi kuhlukile ngokusobala:
– Igazi le-arterial (le-systemic): licebile ngo-oxygen (O₂) futhi liphansi nge-carbon dioxide (CO₂). Leli gazi lisanda kuphuma enhliziyweni (i-ventricle yesobunxele) nge-aorta futhi lithwalwa emzimbeni wonke.
– Igazi lemithambo yegazi (le-systemic): liphansi komoya-mpilo futhi licebile nge-carbon dioxide. Leli gazi liletha umoya-mpilo ezicutshini bese libuyisela i-CO₂ enhliziyweni (nge-vena cava).
Nokho, kubalulekile ukwazi ukuthi ekujikelezeni kwegazi emaphashini kwenzeka okuphambene nalokho:
– Umthambo wamaphaphu (umthambo wamaphaphu) uthwala igazi elingenawo umoya-mpilo lisuka enhliziyweni liye emaphashini.
– Imithambo yamaphaphu (imithambo yamaphaphu) ithwala igazi elinomoya-mpilo elivela emaphashini libuyele enhliziyweni.
Ngakho-ke, incazelo yemithambo yegazi nemithambo yegazi ayinqunywa ngokuthi “icebile nge-oxygen noma cha”, kodwa inqunywa ukuthi igazi ligeleza kanjani enhliziyweni.
Umbala wegazi: obomvu okhanyayo vs obomvu obumnyama
Umehluko emazingeni e-oxygen uthinta ukubukeka kombala:
– Igazi lemithambo livame ukubonakala libomvu ngokugqamile ngoba i-hemoglobin ibopha umoya-mpilo (i-oxyhemoglobin).
– Igazi lemithambo yegazi libonakala libomvu ngokumnyama ngoba liqukethe i-oxyhemoglobin ephansi kanye ne-deoxyhemoglobin eningi.
Kuhle ukucacisa: imithambo yegazi ivame ukubonakala iluhlaza okwesibhakabhaka ngaphansi kwesikhumba, kodwa lokho kungenxa yokuthi ukukhanya kudlula esikhumbeni futhi kubonakala, hhayi ngoba igazi liluhlaza okwesibhakabhaka.
Umfutho wegazi kanye nezinga lokugeleza kwegazi
Imithambo yegazi nemithambo yegazi zisebenza ngaphansi kwezimo ezahlukene zokucindezela:
– Imithambo yegazi ithola igazi ngqo "ephampini" yenhliziyo, ngakho-ke ingcindezi iphakeme. Ngakho-ke, ukugeleza kwegazi emithanjeni yegazi kuvame ukushesha futhi kuzwakala njengokushaya kwenhliziyo emithanjeni ethile (isibonelo, esihlakaleni).
– Imithambo inengcindezi ephansi. Ukugeleza komoya okubuyela enhliziyweni kusizwa ukufinyela kwemisipha yamathambo (isibonelo, ngesikhathi sokuhamba), umehluko wokucindezela ngesikhathi sokuphefumula, kanye nokuba khona kwama-valve emithambo yegazi.
Ekulimaleni, lo mehluko wokucindezela ubonakala ngokucacile: ukopha emithanjeni kuvame ukugeleza futhi kunzima ukukuyeka, kuyilapho ukopha emithanjeni kugeleza kancane.
Ukwakheka kwezindonga zemithambo yegazi: okujiyile vs okunciphile
Umehluko phakathi kwegazi elisemithanjeni yegazi kanye negazi elisemithanjeni yegazi uhlobene nezici zemithambo yegazi:
– Izindonga zemithambo yegazi zijiyile, ziyanwebeka, futhi zicebile ngemisipha ebushelelezi. Lesi sakhiwo sisiza imithambo yegazi ukuba imelane nomfutho ophezulu futhi igcine ukugeleza kwayo kuzinzile.
– Izindonga zemithambo yegazi zincane futhi azinwebeki kakhulu. Imithambo yegazi ibamba igazi eliningi ngomfutho ophansi ngakho ayidingi izindonga ezijiyile njengemithambo yegazi.
Ngenxa yokuthi imithambo ingakhula ukuze ikwazi ukuthwala igazi, ivame ukubizwa ngokuthi “izindawo zokugcina igazi” noma izindawo zokugcina igazi zesikhashana emzimbeni.
Ukuba khona kwama-valve: okuvamile kwemithambo yegazi
Esinye sezici ezibaluleke kakhulu ezihlukanisayo:
– Imithambo yegazi ngokuvamile ayinawo ama-valve ngobude bawo (ngaphandle kwe-valve esezansi kwe-outlet yenhliziyo eyingxenye yesakhiwo senhliziyo, njenge-aortic valve).
– Imithambo eminingi inama-valve ahamba ngendlela eyodwa, ikakhulukazi emithanjeni yemilenze nezingalo, ukuvimbela igazi ukuthi ligeleze emuva ngenxa yamandla adonsela phansi.
Lawa ma-valve abaluleke kakhulu kubantu abama isikhathi eside. Uma ama-valve eba buthaka, igazi lingahlangana emithanjeni yemilenze, okuholela emithanjeni evuvukalayo.
Umsebenzi oyinhloko ekusabalalisweni kwegazi nasekubuyeni kwalo
Uma kufingqiwe ngokusekelwe kumsebenzi:
– Imithambo yegazi isebenza ukuletha umoya-mpilo, izakhamzimba, nama-hormone ezithweni nasezicutshini (ikakhulukazi ekujikelezeni kwegazi).
– Imithambo isebenza ukubuyisela igazi enhliziyweni, ithwale imfucuza ye-metabolic, futhi isize ukugcina umthamo wegazi uzinzile ekujikelezeni kwegazi.
Lokhu kokubili akuhlukaniseki. Imithambo yegazi engenamithambo yegazi ingabangela ukuba igazi "livaleleke" ezicutshini; imithambo yegazi engenamithambo yegazi ingabangela ukuba izicubu zingatholi umoya-mpilo.
Indawo yokwakheka komzimba kanye nokuvikelwa kwawo
Ngenjwayelo:
– Imithambo yegazi ivame ukujula futhi ivikelwe, ngoba uma ilimele ingabangela ukopha okukhulu ngenxa yokucindezeleka okuphezulu.
– Imithambo eminingi iseduze nobuso besikhumba (isibonelo, imithambo engalweni), ngakho kulula ukuyibona futhi ivame ukuba yindawo yokukhipha igazi noma ukufakwa kwe-IV.
Kodwa-ke, lokhu akulona iqiniso ngokuphelele; kukhona nemithambo yegazi engajulile kanye nemithambo yegazi ejulile impela, kuye ngendawo yomzimba.
Izibonelo zemithambo emikhulu kanye nemithambo yegazi
Ukuze sikuqonde, nansi izibonelo zemikhumbi emikhulu:
Imithambo emikhulu:
– I-Aorta (umthambo omkhulu kunayo yonke)
– Umthambo we-carotid (oya ebuchosheni)
– Umthambo we-femoral (oya emlenzeni)
Imithambo eyinhloko:
– I-vena cava ephezulu nephansi (ukubuyela enhliziyweni)
– Umthambo we-jugular (osuka ekhanda/entanyeni)
– Umthambo we-Saphenous (umthambo omkhulu emlenzeni ovame ukuhlotshaniswa nemithambo ye-varicose)
Ubudlelwano nokuhlolwa kwezokwelapha
Ekwelapheni, umehluko phakathi kwalokhu okubili uwusizo futhi:
– Amasampula egazi lemithambo yegazi avame ukuthathwa ukuze ahlolwe njalo elabhorethri ngoba kulula ukuwathola futhi anengcindezi ephansi.
– Amasampula egazi lemithambo yegazi ayathathwa ukuze kuhlolwe okukhethekile njengokuhlaziywa kwegesi egazini (ABG), isibonelo ukuhlola amazinga omoya-mpilo, i-carbon dioxide, kanye nebhalansi ye-acid-base ezigulini ezinezinkinga zokuphefumula.
Ukudonsa igazi emthanjeni kuvame ukuba buhlungu kakhulu ngoba imithambo ijule kakhulu futhi inezinzwa eziningi ezizungezile.
Isiphetho
Umehluko phakathi kwegazi elisemithanjeni yegazi kanye negazi elisemithanjeni yegazi udlulela ngale kwegazi “elicebile ngo-oksijini” noma “elimpofu ngo-oksijini,” kodwa futhi uhlanganisa indlela yokugeleza kwegazi eya enhliziyweni, ingcindezi, umbala, isakhiwo semithambo yegazi, ukuba khona kwama-valve, kanye nemisebenzi yawo yomzimba. Imithambo yegazi ithwala igazi lisuke enhliziyweni ngaphansi kwengcindezi ephezulu kanye nezindonga ezijiyile, kuyilapho imithambo yegazi ibuyisela igazi enhliziyweni ngaphansi kwengcindezi ephansi, enezindonga ezincane, kanye nama-valve okuvimbela ukugeleza kwegazi emuva. Ukuqonda lo mehluko kusisiza siqonde ukuthi umzimba ulondoloza kanjani impilo—ukuletha umoya-mpilo nezakhamzimba ngendlela efanele ngenkathi kususwa ngempumelelo imfucuza ye-metabolic.
Uma uthanda, ngingangeza ithebula lokuqhathanisa elifushane (imithambo yegazi vs imithambo yegazi) noma inguqulo yesayensi kakhulu yalesi sihloko yemisebenzi yesikole/yasekolishi.
