Umsebenzi ophambili we-placenta vumela utshintshiselwano lwemetabolism kunye negesi phakathi kwegazi lomntwana kunye nelomama. Noko ke, asikuphela komsebenzi enawo, njengoko siza kubona kweli nqaku. Kwakhona kubalulekile ukwazi ukuba indawo ye-placenta, nangona idla ngokuchaphazela ukuzalwa komntwana, iyenzeka kwezinye iimeko ezithile, enye esiza kuthetha ngayo namhlanje, i-previa okanye i-placenta ephantsi.
I-fetus kunye ne-placenta zidityaniswe enye kwenye ngentambo ye-umbilical ngelixa i-organism yomama inxibelelana ngokuthe ngqo ne-placenta ngeengxowa ezizaliswe igazi ezibizwa ngokuba. igazi lacunae.
Yintoni i-placenta?
Lilungu elivuthulukayo, ke ngoko, elethutyana, elenza kwi isibeleko ngexesha ukukhulelwa. I-placenta inoxanduva lokondla, ukukhusela kunye nokuncedisa ukukhula komntwana.
Iqhelekile kumfazi okhulelweyo kunye nosana olungekazalwa. Enye inxalenye yemvelaphi kamama (yenziwe yi-endometrium yesibeleko elungisiweyo okanye evuthulukileyo), ngelixa elinye liphuma kwi-fetus (yenziwe nge-chorionic villi). I-placenta, ke ngoko, imele iingcambu zomntwana ongekazalwa kumhlaba kamama.
Imisebenzi ye-placenta
Njengoko sele siphawulile, i-placenta isebenza njengotshintshiselwano lwe-metabolic kunye negesi phakathi kwegazi lomntwana kunye nelomama, kodwa ayiphelelanga apho, yenza neminye imisebenzi emininzi, endiya kukhankanya eyona ibalulekileyo:
- inika ioksijini kwi-fetus kwaye isuse i-carbon dioxide ngokusebenzisa umqobo we-placental, oko kukuthi, umgca omncinci weeseli ezahlula i-chorionic villi kwigazi likamama;
- icoca kwaye ilawule ulwelo amalungu omzimba we-fetus;
- inegalelo kumntwana ongekazalwa izondlo eziyimfuneko, kubandakanywa i-glucose, i-triglycerides, iiprotheni, amanzi, iivithamini kunye neetyuwa zeminerali ngenxa yokunyanzeliswa kwayo ngokubhekiselele kwezi zondlo ezikhoyo kwigazi lomama;
- ivumela ukudlula kwe izilwa-buhlungu nge-endocytosis kwaye kwangaxeshanye ikhusela iintsholongwane ezininzi (ngaphandle kwezinye izinto, ezifana ne-rubella virus kunye ne-toxoplasmosis protozoa);
- kuthintela ukudlula kwezinto ezininzi eziyingozi kumntwana ongekazalwa, nangona ezinye zisenokudlula kuyo, nto leyo eyenza ingozi kumntwana (icaffeine, utywala, inikotini, amayeza athile, iziyobisi ...);
- ivelisa izinto zehomoni eziyimfuneko ekukhulelweni: chorionic gonadotropin yabantu (HCG), iprogesterone, i-estrogen kunye neprolactin.
Ikweyiphi indawo iplacenta?
Isikhundla se-placenta sixhomekeke kwindawo yokufakelwa kwe-embryo kwi-endometrium, ngoko ke inokuba ngaphambili, ngasemva okanye ecaleni kwaye oku akuchaphazeli ukukhulelwa okanye ukunikezelwa. Nangona kunjalo, kunokwenzeka ukuba ibekwe ngaphantsi kunesiqhelo: kule meko sithetha ngayo i-placenta ephantsi okanye i-previa. Malunga ne-5% yokukhulelwa kwangoko kune-placenta ephantsi, ethi kwiimeko ezininzi ibuyele kwindawo yayo yesiqhelo njengoko ukukhulelwa kuqhubeka. Oku kwenzeka ngenxa yokuba isibeleko, xa sikhula ngobukhulu, sityhala. Ukuxilonga ngokuchanekileyo le meko, indawo yayo kufuneka iqinisekiswe malunga neveki ye-35-36 yokukhulelwa.
Ngokubanzi, oku kufuna i ukuzalwa ngotyando, ngakumbi kwiimeko ze-placenta previa ephakathi. Kule meko, ukuvaleka komlomo wesibeleko kwenzeka okuthintela ukudlula kwe-fetus ngokusebenzisa umsele wokuzalwa.
I-Placenta previa kunye nokuzalwa komntwana kwendalo
Un uzame ukuzalwa kwendalo kwezi meko kunokubangela iminxeba kwi-placenta nto leyo enokukhokelela ekopheni okukhulu okunokubeka engozini impilo kamama nosana. Ukuvavanya ukusebenza kwe-placenta phantsi kweemeko eziqhelekileyo, ipharamitha ethembekileyo ingaphezulu kwayo yonke into yokukhula komntwana: ukuba ubungakanani be-fetus buhambelana noko kulindeleke ngokusekelwe kwiminyaka yobudala kunye nomthamo we-amniotic fluid uqhelekileyo, oko kuthetha ukuba isebenza kakuhle.. Ezinye iiparameters ezivavanywa ngovavanyo lwe-ultrasound yi-uroflowmetry ye-umbilical artery, ehlola ukusebenza kwe-placenta ngokusekelwe kwiimeko ze-fetus, kunye ne-uroflowmetry yemithambo ye-uterine, endaweni yoko ihlola icala likamama.