Kuyini placenta?

Namuhla, "placenta" elithi akusona isimanga. amantombazane Modern bayaziqaphela yokukhulelwa nokubeletha is de kahle than konina kanti ogogo. Nokho, iningi lalezi ulwazi kuhlala. Ngakho namuhla sifuna ukukhuluma ngalokho kuba esibelethweni, umzanyana. Uma uthi nhlá, kunzima ukuqonda? Baby esihlalweni anezakhi ukuvikela umbungu okhulayo emiphumeleni elimazayo futhi ezinobuthi. Empeleni, lokhu umzimba kuyimfihlakalo yangempela futhi simanga semvelo.

ngaphansi kwesivikelo

Placenta - uhlobo izivikeli mzimba. It ukhonza njengelungu umngcele phakathi eziphilayo ezimbili. It placenta inikeza yabo evamile co-khona kanye nokuntuleka ukungqubuzana immunological. Senyanga yokuqala sokukhulelwa - siyisinqumo esinzima kunazo zonke. Ngokwengxenye kungenxa placenta ongakabi kwakhiwa, ngakho umzimba we-embryo evikelwe ngokuphelele. Mayelana 12 amasonto, yena nabo bazibambele mathupha ngokugcwele. Kusukela manje, ulungele ukuba afeze yonke imisebenzi yayo.

Kanjani placenta?

Lena iphuzu elibalulekile, ngaphandle okuyinto thina ngeke bakwazi ukuqhubeka nengxoxo yethu. Igama elithi "I-placenta" iza kithi ezisusela olimini lwesiLatin. Ilihumusha ngokuthi "ikhekhe". Ingxenye esemqoka ngayo villi ekhethekile, okuyinto, sekuqala ukuvela kusukela ezinsukwini zokuqala zokukhulelwa. Nsuku zonke zingabantu legatsha ezingasho. Kulokhu, ngaphakathi kubo kuyigazi womntwana. Ngasikhathi sinye ngaphandle ingena igazi likamama lingahlangani ahlanganiswe izakhi. Okungukuthi, placenta athwala ukuhlukaniswa umsebenzi kuqala. Lokhu kubaluleke kakhulu ngoba lokhu umzimba ulawula exchange of izinto phakathi izinhlelo ezimbili avaliwe. Okuvumelana nala mazwi, ohlangothini zangaphakathi nezangaphandle umzanyana has a isakhiwo ezahlukene. Ngaphakathi, kuba bushelelezi. Ohlangothini olungaphandle - emangelengele, Lobed.

isithiyo umsebenzi

Lisho ukuthini igama elithi "isithiyo esinomhlapho"? Ake digress okuncane isiqondiso physiology izinqubo. Njengoba sekushiwo, kuba villi eyingqayizivele ukunikeza umzimba phakathi nowesifazane umbungu. igazi nal kuletha ingane oxygen ne izakhi, futhi ukunika i-fetus we abakhulelwe intombazane-carbon dioxide. uhlelo Excretory baze babe munye amabili. Futhi lokhu imfihlakalo enkulu. isithiyo esinomhlapho ehlukanisa segazi sikanyoko nele-fetus kahle kangangokuthi bakwazi akuhlangani.

Uma uthi nhlá, kubonakala sengathi Amazing, kodwa amabili ahlukaniswe uhlelo esiyingqayizivele semithambo odongeni ulwelwesi. It ngokukhetha sihamba lokho kubalulekile sokuthuthukiswa umbungu. Ngakolunye uhlangothi, ezinobuthi, izinto elimazayo noma eyingozi agcinwayo lapha. Ngakho-ke, odokotela bathi kusukela emasontweni angu-12 umama okhulelwe isivele kungenzeka uphumule kancane. I-placenta uyakwazi ukuvikela izinto eziningi ezingezinhle umzimba wengane.

Kuphela ebaluleke kakhulu

Umgoqo esinomhlapho kukhona zonke izakhamzimba ezidingekayo nomoya-mpilo. Uma udokotela uyaphawula ukuthuthukiswa okungavamile ezingenzeka embungwini, kungaba nika imithi ethize ukwandisa igazi ligeleze placenta. Ngakho, ukwandisa, umoyampilo ongena ingane. Nokho, akubona bonke ngakho elula. I Ukubambezeleka diaphragm eziqukethwe igazi amagciwane likamama amagciwane, kanye amasosha omzimba lapho kukhiqizwa lapho ukushayisana Rhesus. Lokho isakhiwo esiyingqayizivele lokhu ulwelwesi ilungiselelwe ukuze alondoloze fetus in ezihlukahlukene ezimweni.

Akunakwenzeka ukuba uqaphele selectivity eliphezulu ukwahlukanisa. Caught isithiyo esinomhlapho unesimo esifana ehlukile unqobe lo umngcele ubheke umama ne-fetus. Ngokwesibonelo, fluorine kulula kakhulu futhi ngokushesha lingena owesifazane ukuba ingane, kodwa hhayi sekudlule emuva. Isimo siyefana ne uxhumano lokudlulisa.

Ngenxa okukhona ukulawulwa umzimba?

Sesivele watshela umfundi ukuthi placenta ehlukanisa umama lymph nele-fetus. Njengoba Uyinhloboni wakwazi ukusebenzisa indlela enjalo esiphelele imigomo, uma leso sidingo kuza ngokusebenzisa isithiyo, futhi okulimazayo, imisiwe? Eqinisweni, sikhuluma lapha izindlela mayelana amabili nje. Ngokulandelayo, ukubukeka kancane sihlolisise ngamunye wabo.

Okokuqala sinesithakazelo kwesikwenzayo kulawulwa ukugeleza ezibalulekile, izakhi. Kulula ngokwanele. Lipids, ama-carbohydrate, amaprotheni namavithamini njalo etholakala ngaphakathi kweengazi zikamama. Ngakho, umzimba ungase ukhiqize wesifunda olinganiselayo. It ekuqaleni kuqondwe ukuthi lokuhlushwa izinto ezithile egazini kukamama kanye nengane lihlukile.

I permeability umzanyana

Kunzima kakhulu lapho ukhuluma ngani ezinobuthi ukuthi ufake umzimba abakhulelwe thina. I-placenta ehlukanisa ama-lymph kanye igazi. Ngakho, labo wobuthi eguquka egazini sikanina, musa ukuwela Lihle ezingenzeka embungwini. Nokho, edlulisa baphendukela izihlungi yemvelo (isibindi nezinso) ngefomu asalile Basaba ungakulimaza ingane. Iqiniso lokuthi ngephutha sibhajwe umzimba kanina izinto (amakhemikhali, izidakamizwa) kunzima kakhulu ukuyeka. Bavame bavame ukuba adabule umgoqo esinomhlapho.

Limited isithiyo umsebenzi

Nature ababengazange bazicabange ukuthuthukiswa umkhakha yesimanje. Ngakho-ke, imikhiqizo umkhakha chemical kulula ukuba kudlule isithiyo zemvelo. Bona ziyingozi ukukhula nokuthuthuka umbungu. I degree of Ukungena umzanyana kuxhomeke izakhiwo kanye nezici efana ethile. Sizokwenza basho izikhathi ezimbalwa kuphela, eqinisweni kunabaningi. Ngakho, izidakamizwa kokuba isisindo yamangqamuzana (ngaphansi kuka-600 g / Mol) zifana umgoqo esinomhlapho ngokushesha. Ngesikhathi esifanayo, labo babe nesilinganiso esiphansi, neze zingene. Isibonelo, lokhu nge-insulini kanye heparin, okungaba ngaphandle kokwesaba ebekiwe ngesikhathi sokukhulelwa.

Kukhona esinye isibonakaliso. izinto fat-encibilikayo is ngcono kakhulu ukungena ngokusebenzisa placenta kuka amanzi encibilikayo. Ngakho-ke, compounds hydrophilic ezinjani ngaphezulu. Ngaphezu kwalokho, odokotela bayazi ukuthi ematfuba Ukungena izinto ngokusebenzisa placenta incike isikhathi sokuhlala zomuthi egazini. Yonke imithi eside oyibamba eziyingozi kakhulu kunalawo zazo ngokushesha akheka.