Uhlelo Lokuphefumula Ezinhlanzini
Izinhlanzi ziyizidalwa zasemanzini ezinesimiso sokuphefumula esihluke kakhulu kwesezilwane zasemhlabeni. Njengezilwane zasemanzini, ziye zakha izakhiwo nezindlela ezizivumela ukuthi zithole umoya-mpilo oncibilikisiwe emanzini. Lena inqubo ethakazelisayo, esebenza kahle kakhulu, futhi ehlukile kulokho esikubona ezilwaneni zasemhlabeni. Lesi sihloko sizochaza ngokuningiliziwe uhlelo lokuphefumula ezinhlanzini, kusukela esisekelweni salo sokwakheka komzimba kuya ezindleleni zalo zokusebenza kanye nezici ezithonyayo.
Ukwakheka Kokuphefumula Ezinhlanzini
Uhlelo lokuphefumula lwezinhlanzi luqukethe izingxenye eziningana eziyinhloko:
1. Ama-Gill: Isitho sokuphefumula esiyinhloko enhlanzini. Ama-Gill ayizakhiwo ezinemithambo yegazi eminingi ezitholakala ezinhlangothini zekhanda lenhlanzi, ezivikelwe yisimbozo esibizwa ngokuthi i-operculum.
2. Izingcezu ze-Gill: Izakhiwo ezinde, ezifana neminwe ezitholakala ezingcezu ze-gill. Ingcezu ngayinye ye-gill inamagatsha amaningi amancane abizwa ngokuthi i-secondary lamellae. Ama-lamellae andisa indawo yobuso be-gill, okuvumela ukushintshana kwegesi okuphumelelayo phakathi kwegazi namanzi enhlanzi.
3. I-Operculum: Isembozo esiqinile esimboza futhi sivikele ama-gill.
4. Uhlelo Lokujikeleza Kwegazi: Luqukethe inhliziyo enamakamelo amabili (i-atrium ne-ventricle), epompa igazi liye ema-gill bese lidlulela kuwo wonke umzimba.
Indlela Yokuphefumula
Ukuthathwa Komoya-mpilo
Izinhlanzi zithola umoya-mpilo emanzini ngenqubo eyaziwa ngokuthi ukuphefumula kwamagill. Le nqubo ingafingqwa ngezinyathelo eziningana ezibalulekile:
1. Ukungena Emanzini: Inhlanzi ivula umlomo wayo bese amanzi engena emlonyeni.
2. Ukudlula kwamanzi ngemicu yokuphefumula: Ngokuvala umlomo nokuvula i-operculum, amanzi aphoqeleka ukuthi adlule emicu yokuphefumula ehlelwe kahle.
3. Ukushintshana Kwegesi: Njengoba amanzi edlula ku-lamella yesibili, umoya-mpilo emanzini uyasakazeka nge-membrane encane uye kuma-capillary egazi ku-lamella. Ngokuphambene nalokho, i-carbon dioxide egazini iyasakazeka iye emanzini.
4. Ukuphelelwa Yigesi: Ngemva kokushintshana kwegesi, amanzi angenayo i-oxygen manje akhishwa nge-operculum.
Ukusebenza Kahle Kokushintshana Kwegesi
Ukuze uqonde ukuthi le ndlela isebenza kahle kangakanani, kubalulekile ukuqonda umqondo wokugeleza kwamandla kagesi okuphikisanayo:
– I-Countercurrent: Igazi elisezinhlayiyeni zegill ligeleza ngokuphambene nokugeleza kwamanzi. Lokhu kuvumela ukugeleza kokugxila komoya-mpilo okuqhubekayo ku-lamellae, okwenza kube ngcono ukumuncwa komoya-mpilo kanye nokukhishwa kwe-carbon dioxide.
Lokhu kushintshashintsha kuqinisekisa ukuthi igazi lihlala lihlangana namanzi anokuqukethwe okuphezulu komoya-mpilo, noma ngabe igazi likhishwe umoya-mpilo kakhulu, okuyinto ebingenakwenzeka uma igazi namanzi kugeleza ngendlela efanayo.
Izici Ezithinta Ukuphefumula
Kunezici eziningana zangaphandle nezangaphakathi ezithinta ukusebenza kahle kokuphefumula ezinhlanzini:
1. Izinga Lokushisa Lamanzi: Ukuncibilika komoya-mpilo emanzini kwehla ngokushisa okwandayo. Ngakho-ke, izinhlanzi ezihlala emanzini afudumele zingadinga ukulungiswa okukhethekile ukuze zibhekane nokulinganiselwa komoya-mpilo.
2. Usawoti: Amanzi anosawoti aqukethe umoya-mpilo oncibilikisiwe omncane kunamanzi ahlanzekile. Izinhlanzi zasemanzini anosawoti zinezindlela ezikhethekile zokuqinisekisa ukuthi zithola umoya-mpilo owanele.
3. Umsebenzi Wezinhlanzi: Izinhlanzi ezikhuthele kakhulu zinesidingo esikhulu se-oxygen. Ngakho-ke, zingase zibe nama-gill athuthukile noma zisebenzise amanye amasu okwandisa ukumuncwa kwe-oxygen.
4. Ikhwalithi Yamanzi: Ukungcola kanye nezinto ezingcolisayo emanzini kungalimaza ama-gill futhi kuphazamise ukusebenza kahle kokuphefumula. Isibonelo, amazinga aphezulu e-ammonia angalimaza amaseli ama-gill, anciphise ikhono lezinhlanzi lokungenisa umoya-mpilo.
Ukuguqulwa Okukhethekile Kwezinhlanzi
Izinhlobo ezahlukene zezinhlanzi zinezinhlobo ezihlukile zokushintshashintsha ngokusekelwe endaweni yazo yokuhlala.
1. Izinhlanzi Ezindaweni Ezingenawo Umoya-mpilo Ombi: Ezinye izinhlanzi, njenge-gourami, ziye zakha izitho zokuphefumula ezengeziwe njenge-labyrinths ezizivumela ukuthi zithathe umoya-mpilo ngqo emoyeni.
2. Izinhlanzi Ezinezindawo Ezikhethekile Zokuhlala: Ezinye izinhlobo zezinhlanzi, njenge-eel kagesi, zingasebenzisa isikhumba sazo njengendawo eyengeziwe yokuphefumula.
3. Izinhlanzi Ezinokuguquguquka Kwemishini: Ezinye izinhlanzi zinezindlela ezikhethekile zokwandisa ukusebenza kahle komoya wokungenisa umoya ezimbotsheni. Isibonelo, oshaka banezimbobo ezingemuva kwamehlo ezisiza ekujikelezeni amanzi ezimbotsheni, ikakhulukazi uma zimile.
Ukuqhathaniswa Nezilwane Zasezweni
Kukhona umehluko omkhulu endleleni izilwane zasemhlabeni nezasemanzini (kufaka phakathi izinhlanzi) ezimunca ngayo umoya-mpilo. Izilwane zasemhlabeni zithembele emaphashini ukuze ziphefumule, lapho umoya-mpilo ovela emoyeni usakazeka khona ungene egazini nge-alveoli. Ngenxa yokuthi ukugcwala komoya-mpilo emoyeni kuphakeme kunasemanzini, lezi zilwane zidinga izakhiwo ezahlukene ukuze zimunce kahle futhi ngokushesha.
Kunalokho, izinhlanzi zidinga izakhiwo nezindlela eziklanywe ngokukhethekile ukuze kuvunyelwe umoya-mpilo ukuthi usabalale emanzini ungene egazini. Ukusebenza kahle kwalesi simiso kuyisimangaliso sokuziphendukela kwemvelo, okuvumela izinhlanzi ukuba ziphile futhi zichume ezindaweni eziningi zasemanzini eMhlabeni.
Isiphetho
Uhlelo lokuphefumula lwezinhlanzi luyisibonelo esithakazelisayo sokuzivumelanisa kwezinto eziphilayo okuvumela ukuphila ngaphansi kwamanzi. Kusukela ekwakhiweni okuyinkimbinkimbi kwe-anatomiki kuya ezindleleni ezisebenzayo zokulwa nokugeleza, izinhlanzi zithuthukise izixazululo zokuqinisekisa ukuthi zithola umoya-mpilo owanele naphezu kokuhlala ezindaweni ezivame ukungabi nalesi sakhi esibalulekile. Ukuzivumelanisa okukhethekile kwezinhlobo ezahlukene nakho kubonisa izindlela eziningi imvelo engathola ngazo izixazululo zezinselele ebhekene nazo. Ucwaningo olwengeziwe lwalezi zinhlelo lunganikeza ukuqonda okujulile kokuthi impilo ingavumelana kanjani futhi ichume kanjani ezimweni ezahlukahlukene futhi ezivame ukuba nzima.
