Isakhiwo Semithambo Yegazi
Imithambo yegazi iyisici esibalulekile sesimiso senhliziyo nemithambo yegazi, esinomthwalo wokujikeleza igazi emzimbeni wonke. Umsebenzi wayo ubalulekile ekugcineni i-homeostasis, ukuhlinzeka nge-oxygen nezakhamzimba ezicutshini, kanye nokuthutha imfucuza ukuze isuswe. Ukuze uqonde ukuthi lolu hlelo lusebenza kanjani, kubalulekile ukuqonda isakhiwo semithambo yegazi, izinhlobo zayo ezahlukene, kanye nemisebenzi yayo.
Izinhlobo Zemithambo Yegazi
Ngokuvamile, kunezinhlobo ezintathu eziyinhloko zemithambo yegazi: imithambo yegazi, imithambo yegazi kanye nama-capillary. Ngayinye inesakhiwo kanye nomsebenzi othile.
1. Imithambo yegazi:
Imithambo yegazi inesibopho sokuthwala igazi elinomoya-mpilo lisuka enhliziyweni liye emzimbeni wonke. Imithambo yegazi inezindonga ezijiyile nezinwebekayo, ezivumelana nomfutho ophezulu okhiqizwa yinhliziyo lapho ipompa igazi. Udonga lwemithambo yegazi lunezendlalelo ezintathu:
– I-Tunica Intima: Ingqimba engaphakathi kakhulu ethintana ngqo negazi. Yakhiwa amaseli e-endothelial abushelelezi ukuze kuncishiswe ukungqubuzana negazi eligelezayo.
– I-Tunica Media: Ingqimba ephakathi ebanzi kakhulu, eyakhiwe yimisipha ebushelelezi kanye nemicu enwebekayo. Le ngqimba ivumela imithambo yegazi ukuthi imelane nomfutho wegazi futhi ilawula ububanzi be-lumen yemithambo yegazi ngokufinyela kwemisipha okubushelelezi kanye nokuphumula.
– I-Tunica Adventitia: Ingqimba engaphandle eyakhiwe izicubu ezixhumanisayo. Le ngqimba inikeza ukwesekwa kwesakhiwo kanye nokuguquguquka kwemithambo yegazi.
Ngaphezu kwalokho, imithambo emikhulu efana ne-aorta inesendlalelo esengeziwe esiza ekunciphiseni nasekulinganiseni umfutho wegazi okhuphukayo lapho inhliziyo ifinyela.
2. Imithambo:
Imithambo yegazi iyimithambo yegazi ethwala igazi ibuyele enhliziyweni, ngokuvamile equkethe igazi elicebile nge-carbon dioxide. Izindonga zemithambo yegazi zincane futhi azinwebeki kahle kunemithambo yegazi, njengoba zithola umfutho wegazi ophansi. Imithambo yegazi iphinde ibe nama-valve avimbela ukugeleza kwegazi emuva, ikakhulukazi emithanjeni emide njengaleyo esemilenzeni.
Isakhiwo esiyisisekelo semithambo yegazi sifana nesemithambo yegazi, esakhiwe ngezingqimba ezintathu (intima, media, kanye ne-adventitia), kodwa sine-tunica media encane kanye ne-tunica adventitia ejiyile.
3. Ama-Capillaries:
Ama-capillary ayimithambo yegazi emincane enezindonga ezincane kakhulu, equkethe ungqimba olulodwa lwamaseli endothelial, okwenza kube lula ukushintshana kwamagesi, izakhamzimba, kanye nemikhiqizo engcolile phakathi kwegazi nezicubu ezizungezile. Inethiwekhi yama-capillary yakha ibhuloho phakathi kwama-arterioles (amagatsha amancane emithambo yegazi) nama-venule (amagatsha amancane emithambo yegazi). Ubukhulu bawo obuncane kakhulu buvumela indawo enkulu yokuxhumana, okunikeza izimo ezinhle kakhulu zokushintshana kwezinto.
Umsebenzi kanye Nomsebenzi Wesistimu Yemithambo Yegazi
Indima eyinhloko yemithambo yegazi ukusekela ukujikeleza kwegazi okusebenzayo, ukuqinisekisa ukuthi amaseli emzimbeni wonke athola izakhamzimba ezidingekayo kanye nomoya-mpilo futhi asuse imfucuza. Imisebenzi kanye nezinqubo zemithambo yegazi zifaka:
– Ukusatshalaliswa Komoya-mpilo Nezakhamzimba: Igazi elimpontshelwa yinhliziyo lithwala umoya-mpilo kanye nezakhamzimba ezivela emaphashini kanye nohlelo lokugaya ukudla emzimbeni wonke ngemithambo yegazi.
– Ukuqoqwa Nokuthuthwa Kwemfucuza: Ngemva kokuba umoya-mpilo nezakhamzimba sezisetshenziswa amangqamuzana omzimba, i-carbon dioxide neminye imikhiqizo ye-metabolic ithuthwa ibuyiselwe enhliziyweni ngemithambo ukuze ikhishwe emzimbeni noma icutshungulwe kabanzi.
– Ukulawulwa Komfutho Wegazi: Imithambo yegazi, ikakhulukazi imithambo yegazi, idlala indima ebalulekile ekulawuleni umfutho wegazi ngokusebenzisa izindlela zokunciphisa imithambo yegazi (ukuncipha kwemithambo yegazi) kanye nokwandisa imithambo yegazi (ukwandiswa kwemithambo yegazi).
– Ukulawula Izinga Lokushisa Lomzimba: Imithambo yegazi nayo idlala indima ekulawuleni izinga lokushisa ngokulawula ukugeleza kwegazi esikhumbeni. Uma kushisa, imithambo yegazi iyavuleka ukuze ikhiphe ukushisa endaweni ezungezile. Ngokuphambene nalokho, uma kubanda, imithambo yegazi iyancipha ukuze kulondolozwe ukushisa komzimba.
Izifo Zemithambo Yegazi
Imithambo yegazi ingathinteka yizimo eziningana zezokwelapha ezingathinta kakhulu impilo yomuntu. Ezinye zazo zifaka:
– I-Atherosclerosis: Isimo lapho i-fatty plaque yakheka khona ezindongeni zangaphakathi zemithambo yegazi, inciphisa ukuqina kwayo futhi inciphise indlela yokugeleza kwegazi. Lokhu kungaholela esifweni senhliziyo futhi kwandise ingozi yokushaywa yisifo sohlangothi.
– Imithambo ye-Varicose: Kwenzeka lapho imithambo ikhula futhi ikhukhumala ngenxa yama-valve emithambo angasebenzi kahle, okuvame ukwenzeka emilenzeni ngenxa yokucindezela okukhulu kokuma.
– I-Aneurysm: Ukwanda okungavamile kodonga lwemithambo yegazi ngenxa yobuthakathaka, okungaqhuma futhi kubangele ukopha okukhulu kwangaphakathi.
– Umfutho wegazi ophakeme (Umfutho wegazi ophezulu): Umfutho wegazi ophakeme njalo ubeka ukucindezeleka okukhulu ezindongeni zemithambo yegazi, okubangela ukulimala kwemithambo yegazi nezinye izitho zomzimba.
Isiphetho
Imithambo yegazi idlala indima ebalulekile ekugcineni impilo yonke kanye nokusebenza komzimba. Ukuqonda isakhiwo sayo kanye nomsebenzi wayo kusiza ukuqonda ukuthi uhlelo lokujikeleza kwegazi lusebenza kanjani futhi kunikeza ukuqonda ngezimo ezahlukene zezokwelapha ezingathinta lo msebenzi. Ukutshala imali endleleni yokuphila enempilo, okuhlanganisa ukudla okulinganiselayo kanye nokuzivocavoca njalo, kungasiza ekugcineni impilo yemithambo yegazi, ukuvimbela izifo, kanye nokuthuthukisa ikhwalithi yokuphila.
