Igazi

Igazi lingamanz’ abomvu asemizimbeni yabantu nakwimizimba yezilwanyana. Igazi lityhalwa  zizinto ezincinane kakhulu eziphilayo neziqumbene ndawoninye ezikhutshwa yintliziyo, ngeenjongo zokokuba igazi lizise izakha-mzimba kunye nomoya ococekileyo kwizihlunu zemizimba yethu. Ikwaligazi eligutyula konke ukungcola okuvela emzimbeni kunye nomoya ongcolileyo, lowo uvela emzimbeni ngamanye amazwi. 

Lenziwe ngantoni igazi
Igazi lenziwe ngengamanzi atyheli-buphatsha nangawona adibanisa iimbewu zegazi zitsho zikwazi ukuhlala zidibene zisebenzisana ndawonye kunye nezinye iintlobo-ntlobo zeembewu zegazi — iimbewu zegazi ezibomvu, iimbewu zegazi ezimhlophe kunye neembewu zegazi ezimisa ukopha okanye ukumpompoza kwegazi ekuthiwa ziiplatelets. Iiplatelets zinceda ngokunqamla ukopha. Iigazi elinesakhamzimba i-iron eneproteni ifumaneka kwiimbewu zegazi ezibomvu. Iimbewu ezimhlophe apha egazini zona ziluncedo ekulweni nosuleleko zize ziphinde zinyange amanxeba. 

 Nge-Plasma 
Iplasma yegazi yinto engamanzi atyheli adada apha egazini. Nayo ke yenziwe ngezakha-mzimba, iityuwa zomzimba ezinyibilikayo, umoya ohlaziya nongcolisa umzimba, amagatya alawula ukusebenza komzimba engasebenzisi ziproteni, ukungcola okungaphakathi emzimbeni, izakhamzimba zendalo ezingamafutha omzimba, kunye neeproteni.

Ezi proteni zibaziinqwelo zokuthutha ezinye izakha-mzimba ezincinane kakhulu ngegazi, zibengantibodies| amajoni omzimba (nabizwa ngokuba zii-immunoglobulins), zijongana neziganeko zokwenzeka kwamahlwili, kunye namagatya eeproteni. I-Plasma ayinayo iproteni  eyenza amahlwili yiyo le nto kuthiwa xa ibizwa yi-serum kwaye ayinakubalihlwili. Zi-3 iilitha zeplasma ezinokufumaneka kubantu abadala. IPlasma ingamanzi, singathi amanzi akuyo amalunga nama-(90%). Kananjalo iplasma inobunzima begazi obunokude bubengama-55%. 

 iimbewu ezibomvu egazini 
Elinye igama leembewu zibomvu egazini kuthiwa zii-erythrocyte. 'i-Erythro' ithetha ukuthi bomvu; elithi cyte lithetha ukuthi mbewu. Aba nobumba bathi BGM basis ishunqulelo ngolu hlobo  ‘’’b’’’omvu ’’’g’’’azi mbewu.

Imbewu ebomvu egazini ithwala umoya ococekileyo kunye nomoya ongcolileyo ziwusa kuwo wonke umzimba.  Iimbewu zemizimba yethu zifuna umoya ococekileyo ukuze siphile. Kwakhona ezi mbewu ziyawenza umoya ongcolileyo sitsho sithi ke kukungcola oko. Imbewu ebomvu egazini izisa umoya ococekileyo othe xaxe kuwo wonke umzimba.  Iphinde kwale mbewu, iwuthwale iwukhuphele ngaphandle emzimbeni umoya ongcolileyo. 

IiBGM zizaliswe yiiron eneproteni kwimbewu ebomvu yegazi. Ngesingesi ke kuthiwa yihaemoglobin. Singatsho ngelipheleleyo okokuba yiproteni. Yenzelwe ukuba ithwale umoya omninzi ococekileyo iwusasaze kuwo wonke umzimba.  Njengoko sele sitshilo, le haemoglobin ineiron kuyo. Xa zizombini ke iiiron kunye nalo moya ucocekileyo ziyitsho ibebomvu le haemoglobin ngombala.  Yhiyo le nto igazi silibona libomvu nje. Kukho into ekuthiwa yiErythropoietin ekuyeyona ikhuthaza ukwenzeka kwale mbewu ibomvu egazini.  Uhlobo lwegazi amajoni akhutshwa yinkqubo yangaphakathi emzimbeni ukuba alwe nokuyingozi okungena emzimbeni athwalwa apha kumphezulu wembewu yegazi ebomvu. 

IBGM ikwanceda ukuba igazi lihlale likwimo efanelekileyo pH. Kufuneka uze ube uphilile kakuhle ngokwasegazini libe kwizinga le-ph ka 7.4. Ukuba nje likhe langaphezulwana okanye langaneno kuno-7.4, umntu usenokugula kakhulu okanye angade abe uyasweleka. IiBGM zizo ezilawula ipH yegazi. Ibuffer yiyo emisa utshintsho kwipH. Iiproteni kunye nomoya ongcolileyo kwiBGM zimisa utshintsho olwenzeka egazini. 
Ukuba kuthe kanti awunayo imbewu ebomvu egazini lakho, uyakufa.  

 Imbewu emhlophe egazini 
imbewu emhlophe egazini idlala indima enkulu kukhuselo lweentsholongwane emzimbeni. Le mbewu ihlasela yonke into engena emzimbeni ibe ingafanelekanga kungena. Ibulala iintsholongwane ezifana neentsholongwane ezosulelayo kunye nee ntsholongwane ezifana nezefiva, nekagawulayo, njalo, njalo.. Ibulala nembewu yomhlaza. Imbewu emhlophe egazini iluncedo kakhulu kuba ilwa nezinye izinto eziyityhefu emzimbeni.  

Le mbewu imhlophe egazini izibhaqa nokokuba ziphi na ezi ntsholongwane apha emzimbeni, emva koko yonde ngazo, zizitshabalalise. IiMGM ziyafika egazini. Ziyakwazi nokuphuma egazini zenjenjeya ukuya kwiindawo apho usuleleko lukhoyo.  IiMGM zenza oku ukuze zilwe neentsholongwane ezidala usuleleko. Ukuba ziye zaphumela ngaphandle egazini zisiya kulwa   nosuleleko, zisenokuphindela kwigazi elityhutyha-tyhutyha umzimba. Ngoko ke iiMGM zikumajelo egazi elijikeleza emzimbeni. 

Elinye igama lembewu emhlophe egazini kuthiwa yileukocyte. U-Leuko uthetha ukuthi ‘mhlophe’. u-cyte uthetha ukuthi ‘cell’. Oonobumba abathi  MGM bashunqulela ngolu hlobo  ’’’m’’’hlophe ’’’g’’’azi ’’’m’’’bewu. Zintathu ezona ndidi zeMGM.  Kukho ezelymphocytes, ezegranulocytes kunye  neemonocytes. Inxalenye yeeMGM zivuthelwa kwiimbewu ezenza umsebenzi ofanayo kwizihlunu zomzimba. 

IiMGM zisebenza ngeendlela-ngeendlela. Ezinye zazo zibulala ziphinde zitye iintsholongwane kunye nembewu zentsholongwane yomhlaza. Ezinye zenza amagosa alwa neentsholongwane. Ezi proteni ziiproteni ezincamathela kwezinye iimbewu zize ziyalele  ezinye iiMGM ukuba zibulale. Ezinye iiMGM zenza iikhemikhali.  Zithi zikhuphe iikhemikhali eziyakulwa nezinto ezingafanelekanga kuba semzimbeni. Ezi khemikhali zidala ukutsha kwindawo ethile apha emzimbeni.  Xa intsholongwane ikugulisa, umzimba uyakubonakalisa oko. Ukuba  intsholongwane iziqhusheka ngaphantsi kwesikhumba somntu ize yenze  usuleleko, siyajika sibebomvu isikhumba sakhe, sitshise, sibebuhlungu kunjalo nje. Oku kubabomvu kwesikhumba, ukutshisa kwaso, kunye neentlungu, zonke ezi ziimpawu zo kutsha okanye ukurhawuka. Oku kubonakalisa okokuba iiMGM zilwa nosuleleko kwaye zibulala intsholongwane. 

 Ii-Platelets 
IiPlatelets zinceda ekwenzeni amahlwili egazi. Platelets are also called 'thrombocytes'. Ihlwili kuxa igazi lithi belingamanzi lisuke lijiye. Umzimba wenza ihlwili legazi xa isikhumba esi siye sasikeka. Oku kunqanda ukopha kakhulu ukuze igazi elininzi lingachithekeli ngaphandle.   

Kubalulekile okokuba igazi lijiye. Kodwa ngamaxesha athile amahlwili egazi angaba mabi okanye abe neziqhamo ezimbi. Ukuba ukujiya kwegazi kuyenzeka ku[blood vessel|mbhobho wegazi apha emzimbeni, kungadala istroke. Ukuba igazi lijiya xa kanye lihamba ngombhobho wegazi oya entliziyweni, oko kungadala isifo sentliziyo (heart attack). Oku ke akuqhelekanga kubantu abatsha nabanempilo.  

Ii-Platelets akukuphela kwento eyenza amahlwili. Zikho neeproteni egazini ezenza amahlwili. Iiplatelets kunye "neeproteni zamahlwili" ziyafuneka ukuze zenze amahlwili alungileyo emzimbeni.

 Livelaphi igazi eli? 
300px|thumb|right|Umboniso wembewu yomongo wethambo ovela ku"Gray's Anatomy".
Imbewu yegazi yenziwa ngumongo wethambo nakw"'ispleen". Umongo yinto ethambileyo ngaphakathi ethanjeni. Bambi ke bade bathi bayahleza, laanto ifunxwayo ke xa kuhlezwa kuthiwa ngumongo. Kukho iimbewu ezikhethekileyo apha kulo mongo, kwaye ubukhulu becala le mbewu yiyo eyenza iimbewu zegazi emzimbeni wakho.  

Iiproteni zeplasma zona zenziwa sisibindi. Amanzi kunye neetyuwa ezinyibilikayo kwi-"plasma" zivela ekutyeni esikutyayo nasemanzini esiwaselayo.

Nangona igazi  lingamanzi, ngezinye iindlela likwaluhlobo  lokunxulumanisa amalungu angaphakathi omzimba. Imbewu yegazi isuka kumongo wethambonakwispleen, kwaye egazini kukwakho ne"micu yeenwebu" ebalulekileyo eluhlobo lwe"fibrinogen". Zonke ezi zisebenza xa kusenzeka  ihlwili legazi.

 Izalathiso 

Category:Basic English 850 words 
Category:Biochemistry
Category:Cardiovascular system