"Nzvimbo yevana", iyo inowanikwa mumubereki munguva yekubata muviri, inonzi "placenta" uye ndiyo imwe yenhengo dzakasiyana-siyana uye dzakakomba dzevanhu. Mabasa epa placenta zvakakwana haagoni kuchinjwa nemhando ipi zvayo yezvigadzirwa zvemishonga kana kugadzirira.
Chii chinonzi placenta?
Muviri uyu unogadzirwa nemasikirwo ekuti huve nechokwadi chezvinhu zvose zvekuzadza kwakakwana kwomwana mukati memukati uye kudzivirira kusununguka nguva isati yasvika kubva pamutoro. Chinhu chakakosha chepentecenta pakuzvitora ndechokuti haisi kusvikirwa kwechibereko chezvinhu zvinokuvadza zvakadai seikotine, doro, zvinodhaka nezvimwe zvakadaro. Zvisinei, izvi hazvizi zvose zvakakosha zvebasa re placenta. Kana iwe uchiratidza kufarira kwakadzama mumabasa ayo uye zvinoreva dzidzo, unogona kudzidza zvinhu zvakawanda zvinofadza.
Ndezvipi mabasa eparcenta?
Panzvimbo yemazuva ano ekugadzirwa kwemishonga, zvakadaro zvinoshanda zve "nzvimbo yemwana" se:
- kushandiswa kwe oksijeni uye carbon dioxide pakati pemidziyo yeropa ye fetus uye pamuviri ;
- kupiwa kwezvibereko kumwana, izvo zvakagoverwa kubva muropa raamai, zvinoitwa. Zvisingazivikanwi zvasara zvinodzokera kumukadzi;
- iyo nhengo yepamusoro inokwanisa kuchengetedza mwana kubva kumavirusi, ma-antibodies, toxin uye mabhakitiriya anopinda mumuviri wemubereki. Ichi chiratidzo chekuita mabasa emuviri;
- iyo endocrine basa relacenta inosanganisira kurega kwezvinhu zvakasiyana, zvichiita sechinhu chekuvhara mukati mukati;
- iyo hormonal function ye placenta inoratidzirwa nekuvhara kwemahomoni anodiwa pakugadziriswa nokukurumidza kwemuviri wemukadzi ane pamuviri kune imwe nzvimbo mutsva kwaari nekuchengetedzwa kwemucheche. Mahomoni eparcenta anomiririrwa ne estrone, progesterone, hCG nezvimwewo.
Kuziva kuti basa rinorevei, rinobatsira amai vari mberi kuti vaone zvakakosha kukosha kwavo uye kuratidzira kunyanya kutarisira hutano hwake.