Imibuzo Yezibonelo kanye Nengxoxo Ngesakhiwo Semithambo Yegazi
Imithambo yegazi iyisici esibalulekile ohlelweni lokujikeleza kwegazi lomuntu, ithutha igazi elinomoya-mpilo nezakhamzimba emzimbeni wonke futhi ibuyisa igazi eligcwele imfucuza elivela ezicutshini zomzimba ukuze licutshungulwe kabanzi. Ekufundeni isakhiwo semithambo yegazi, kubalulekile ukuqonda izingxenye zayo, imisebenzi yayo, kanye nezinkinga ezivamile ezihlangana nazo. Lesi sihloko sihlose ukunikeza izibonelo nezingxoxo ezihlobene nesakhiwo semithambo yegazi.
Izinhlobo Zemithambo Yegazi
Ngaphambi kokuba singene emibuzweni, ake sibukeze kafushane izinhlobo ezintathu eziyinhloko zemithambo yegazi:
1. Imithambo yegazi: Imithambo yegazi ethwala igazi isuka enhliziyweni. Izindonga zayo zijiyile futhi ziyanwebeka ukuze zimelane nomfutho wegazi ophakeme ophuma enhliziyweni.
2. Imithambo yegazi: Imithambo yegazi ebuyisela igazi enhliziyweni. Izindonga zayo zincane kunemithambo yegazi futhi inama-valve avimbela ukugeleza kwegazi emuva.
3. Ama-Capillaries: Imithambo yegazi emincane kakhulu, exhumanisa ama-arterioles nama-venule, futhi iyindawo yokushintshana kwegesi, izakhamzimba, kanye nokungcola phakathi kwegazi nezicubu.
Imibuzo Eyisibonelo Nengxoxo
Okulandelayo yizibonelo zemibuzo evame ukuvela ekufundeni ngesakhiwo semithambo yegazi, kanye nezingxoxo zayo.
Umbuzo 1: Ukwehlukaniswa kwesakhiwo semithambo yegazi
Umbuzo: Chaza umehluko omkhulu ngesakhiwo phakathi kwemithambo yegazi, imithambo yegazi kanye nama-capillary.
Ingxoxo:
Umehluko omkhulu phakathi kwemithambo yegazi nemithambo yegazi usezindongeni zayo. Imithambo yegazi inezindonga ezijiyile nezinwebekayo ngoba kumele imelane nomfutho ophezulu. Udonga lwemithambo yegazi lunezendlalelo ezintathu: i-tunica intima, i-tunica media (ejiyile kakhulu ngoba iqukethe imisipha eminingi ebushelelezi), kanye ne-tunica adventitia.
Ngokuphambene nalokho, imithambo inezindonga ezincane nezithambile ngoba umfutho wegazi uphansi kuzo. Futhi inama-valve avimbela ukugeleza kwegazi emuva, isici esingavamile ukutholakala emithanjeni. Isakhiwo semithambo sifana nesemithambo, kodwa sine-tunica media encane.
Ama-capillary anezindonga ezincane kakhulu, aqukethe ungqimba olulodwa kuphela lwamaseli endothelial, okuvumela ukushintshaniswa kwamagesi nezakhamzimba kalula phakathi kwegazi nezicubu ezizungezile.
Umbuzo 2: Indlela Yokugeleza Kwegazi
Umbuzo: Izindlela zokugeleza kwegazi zihluke kanjani phakathi kwemithambo yegazi nemithambo yegazi?
Ingxoxo:
Ukugeleza kwegazi emithanjeni yegazi kuqhutshwa ukucindezeleka okukhiqizwa yinhliziyo njengoba ipompa igazi. Lo mfutho wegazi ubizwa ngokuthi umfutho wegazi we-systolic. Izindonga ezinwebekayo zemithambo yegazi zisiza ukumelana nokusabalalisa lo mfutho kuyo yonke inethiwekhi yemithambo yegazi.
Ngokuphambene nalokho, ukugeleza kwegazi emithanjeni akushukunyiswa umfutho oqondile ovela enhliziyweni. Ngenxa yokuthi ingcindezi emithanjeni iphansi, ezinye izici zisiza ekuqhubekiseni ukugeleza kwegazi—njengokufinyela kwemisipha yamathambo okucindezela imithambo nama-valve emithanjeni okuvimbela ukugeleza kwegazi emuva.
Umbuzo 3: Umsebenzi wama-Capillaries ku-Gas Exchange
Umbuzo: Iyini indima yama-capillary ekushintshaneni kwegesi phakathi kwegazi nezicubu zomzimba?
Ingxoxo:
Ama-capillary asebenza njengendawo eyinhloko yokushintshana phakathi kwegazi nezicubu ezizungezile. Ngenxa yokuthi izindonga zama-capillary zakhiwe ungqimba olulodwa oluncane lwamaseli endothelial, avumela amagesi, njenge-oxygen ne-carbon dioxide, kanye nezakhamzimba nemikhiqizo engcolile, ukuthi ahambe kalula ngokusabalala. I-oxygen nezakhamzimba ziyasabalala egazini ziye emangqamuzaneni omzimba, kuyilapho i-carbon dioxide nemikhiqizo engcolile isuka emangqamuzaneni iye egazini ukuze ithwalwe.
Umbuzo 4: Izinkinga Nezifo Zemithambo Yegazi
Umbuzo: Qamba futhi uchaze izifo ezimbili ezivamile ezithinta imithambo yegazi.
Ingxoxo:
Izifo ezimbili ezivamile ezithinta imithambo yegazi yi-atherosclerosis kanye nemithambo ye-varicose.
1. I-atherosclerosis yisimo lapho i-plaque yakheka khona odongeni lwangaphakathi lwemithambo yegazi, iyenze iqine futhi inciphise. Lokhu kungavimbela ukuhamba kwegazi futhi kwandise ingozi yezinkinga ezinkulu njengokuhlaselwa yinhliziyo noma isifo sohlangothi. Ukushintsha indlela yokuphila kanye nokwelashwa kungasiza ekulawuleni lesi simo.
2. Imithambo ye-varicose ivuvukele futhi ikhuliswe imithambo evame ukuvela emilenzeni. Lokhu kwenzeka lapho ama-valve emithambo engasebenzi kahle, okubangela ukuba igazi lihlangane futhi imithambo ivuvuke. Nakuba ngokuvamile ingenangozi, imithambo ye-varicose ingabangela ukungakhululeki kanye nezinkinga uma ingelashwa.
Isiphetho
Ukuqonda isakhiwo kanye nomsebenzi wemithambo yegazi kuyisisekelo esibalulekile sokutadisha uhlelo lokujikeleza kwegazi lomuntu. Imithambo yegazi idlala indima hhayi nje ekuthuthweni kwegazi kodwa nasekushintshisaneni kwezakhamzimba kanye nemikhiqizo engcolile kanye nokugcina i-homeostasis yomzimba. Ngokucabangela izibonelo nezingxoxo ezichazwe, kunethemba lokuthi abafundi bazothola ukuqonda okungcono kobunzima kanye nendima ebalulekile yemithambo yegazi emzimbeni womuntu. Njengasezicini eziningi zebhayoloji yomuntu, ucwaningo olwengeziwe nolwazi luyaqhubeka lutholakala, luvula indlela yentuthuko yezokwelapha kanye nokwelashwa okuphumelelayo.
