Ukujikeleza kwegazi emzimbeni

I-circulatory system kuxa igazi lijikeleza lityhutyha-tyhutyha umzimba. Oku kuhamba-hamba kwegazi lijikeleza emzimbeni kwenziwa yintliziyo nayo yonke imithambo bnemibhobho ehamba angalo igazi. 

Imithambo yegazi esebenza njengomzila okanye indlela yegazi eliphuma entliziyweni ibizwa ngokuba ngoo-nothumela. Aba nothumela ke baya bencipha ngokuya bebhekela beyishiya intliziyo. Bathi ke bakubabancinane ngokugqibeleleyo bajike ngoku babe zii-arterioles. Xa bezii-arterioles kulapho bathi baxhumane khona  nemithanjana yomzimba ebizwa ngokuba zii-cappilaries.  

Imithambo yegazi ekuhamba kuyo igazi ilise entliziyweni ngoonobuyisa. Yona imithambo iya ivuleka isiba mikhulu xa isiya isondela entliziyweni. Xa kubuyiselwa igazi entliziyweni le mithambo ingoonobuyisa iya ivuleka ngokuya isondela entliziyweni, ize iye incipha ngokuya isiba kude nentliziyo, le ndawo inciphileyo ke apha koonobuyisa kuthiwa zii-venules.

Imithanjana ezii-Capillaries yona ihamba phakathi kwoonothumela noonobuyisa.  Kodwa ke yona le mithanjana ye-capillaries ithande ukuncipha, yhiyo le nto negama layo livela kwigama lesiLatini elithi capillus okuthetha "iinwele." 

Igazi ke lihamba ngolu hlobo:  liqala entliziyweni→liye kunothumela-→liye kwimithanjana kanothumela→liye kwi-capillary→liyekumthanjana omncinane kanobuyisa i-venule→liye koonobuyisa→
ligqibele entliziyweni. Oku ke kukujikeleza kwegazi emzimbeni okubizwa ngokuba yi-circulation ngesiNgesi. Zimbini ke iintlobo zee-circulations kule nkqubo yokujikeleza kwegazi ebizwa ngokuba yi-circulatory system ngesiNgesi. Eyokuqala yi-systemic circulation yindlela elihamba ngayo igazi kumalungu omzimba amaninzi. Eyesibini inkqubo yi-pulmonary circulation yindlela igazi elityhutyhatyhutyha ngayo nge-miphunga. (I-Pulmonary iththa ukuthi ¨okumalunga nemiphunga¨). Igazi lisebenza kanje ke kwizilwanyana ezanyisayo, kuquka nabantu. Le nkqubo yokujikeleza kwegazi emzimbeni iyohluka kwezinye izilwanyana ezinethambo lomqolo ngandlelana ithile. Izilwanyana ezingenalo ithambo lomqolo  zahluke kakhulu ke zona.  

 I-Systemic circulation 
Igazi elisuka ngakwikhohlo lentliziyo lizele yi-oksijin ne-zakha-mzimba. Izakha-mzimba zizinto ezifunwa ngumzimba wakho ukuze ube nokuphila, izinto ezinje ngee-proteni, amafutha, iikhabhorhidrate, ivithamini, kunye nee-minerali zokutya. Apha phantsi kwale  systematic circulation ke kulapho igazi lizisa khona i-oksijin nezakha-mzimba emzimbeni wakho.  

Igazi elifumaneka kwi-systemic arteries eligcwele i-oksijini nezakha-mzimba liligazi eli-systemic arterial. Ngamany'amaxesha kuthiwa nje liyi-arterial blood. 

Eyona systemic artery yakhe yankulu emzimbeni yi-aorta. Lo ke ngowona mthambo mkhulu emzimbeni othatha igazi elicocekileyo elimpontshwe yintliziyo lilise emzimbeni.    Kule aorta ke kumile amasetyana ee-arteries axananazileyo. Kanti kwakula masetyana ee-arteries axananazileyo, kumile ezinye imfikimfelane zee-arteries. Singathi xa sizijonga zizisizukulwana se-aorta esibizwa ngokuba zii-arterioles.

Kananjalo, eyona mibhobho yegazi yakha yamincinane yimithanjana eyaziwa ngokuba zii-capillaries. Ii-systemic arterioles zijika zingene kwii-capillaries. Igazi elikwii-arterioles liziphokozela kwii-capillaries. Kulapho ke i-oksijini nezakha-mzimba zithi ziphume khona egazini zingene kwi-tissue ejikeleze ii-capillaries. Kwakhona eli gazi naloo lichola-chola ikhabhorndioxide enokugcola kwegazi okuvela kwi-tissue okanye emzimbeni. Ubuxhaka-xhaka bee- capillaries ezisa igazi kule ndawo kuthiwa yi-capillary bed.

Kwelinye icala lalo mthanjana oyi-cappilary, liyajika libe ngumthanjana omncinane kanobuyisa obizwa ngokuba yi-venule ngesi. Le mithanjana ke izii-venules yeyona mithambo yakhe yamincinane kunayo yonke imithambo engonobuyisa. Imithambo engoobuyisa ithatha igazi iliphindisele entliziyweni. Bathi ke ngokuya besondela ngasentliziyweni baye bekhula besiba bakhulu kunangaphambili. Oyena nobuyisa mkhulu kwi-systematic circulation eyenzeka emzimbeni zii-vena cava. Zimbini ii-vena cava. Kukho i-vena cava engezantsi (ekuthiwa yiinferior vena cava ngesiNgesi) nethatha igazi kumazantsi omzimba ilise kwicala elingasekunene kwentliziyo.  (kwi-anatomy, igama elithi inferior lithetha ukuthi ngaphantsi) I-vena cava engasentla (nebizwa ngokuba yi-superior vena-cava) yona ithatha igazi elikumantla omzimba ilise entliziyweni. (igama elithi superior lithetha ukuthi ngasentla).

 I-Pulmonary circulation  
Le ntshukumo yegazi echazwe apha ngasentla yenzeka ngemiphunga kwi-pulmonary circulation.  

Igazi elithathwa ngunobuyisa womthambo i-vena cava ilisa entliziyweni ligcwele i-kharbhondioxide. I-oksijin yayo inganeno kunaleyo ikunothumela (oyi-systemic arterial blood). Icala langasekunene lentliziyo lityhala igazi elikunobuyisa kwi-pulmonary artery. Ize ke yona i-pulmonary artery ithathe igazi ilise emiphungeni. Lisakufika emiphungeni, igazi lihamba nge-pulmonary capillary bed. (Imithanjana yee-cappilaries esemiphungeni). Apha kulapho lifumana i-oksijini ethe eninzi.  Kukwalapha apho ishiya khona i-kharbhondioxide eninzi. (Le nto yenzeka apha ichasene nale yenzeka kwimithanjana yee-capillary beds emzimbeni wonke. Kwi-systemic circulation igazi lishiya i-oksijini lize lithathe ikharbhondioxide).

Emva kokuba lingene kwi-capillary bed, nalo igazi lisiya koo-nobuyisa abazii-pulmonary Eli gazi liphuma kunobuyisa oyi-pulmonary ligcwele yi-oksijin. Oonobuyisa be-pulmonary bathatha igazi balise kwicala langasekunene lentliziyo. Lize ke ngoko igazi liphinde libuyele kwi-systematic circulation kwakhona.  

 I-shunt 
Oonobuyisa be-gut bagqitha esibindini phambi kokuba babuyele kwi-atrium nakwi-ventricle yangasekunene. Le shunt ibizwa ngokuba ngunobuyisa we-hepatic portal. 

Okuthethwa yiyo yonke le nto naku:  Isibindi siyeyona fecthri yeekhemikhali zomzimba. Ithatha izakhamzimba ezikwi-gut, ize izilungiselele okufunwa ngumzimba. Isenokugcina intsalela yezakha-mzimba, okanye ikhulule izakhamzimba ezithe chatha nezikuvimba.  Isenokutshintsha ukwenziwa kweekhemikhali zezakha mzimba ezininzi.   Ngale ndlela yenza okokuba kube lula ukuba iintlobo-ntlobo zokutya zibe zinokusileka.  

 Amaphepha anxulumene nala 

 Amaphepha anxulumene nala 

 Ezinye ii-websites 
 American Medical Association Encyclopedia - The Circulatory System
 Ohio Heart and Vascular Center - pictures
 Circulatory system Citizendium

Category:I-Physiology