Iviki le-13 ekuthuthukiseni i-fetal liphawuleka kakhulu, ngalesi sikhathi ukuthi ubudlelwano buyasungulwa ohlelweni "lomama wengane".
Ake sicabangele indlela ingane iqala ngayo ngale nkathi yokukhulelwa.
I-Placenta
Ngalesi sikhathi, i-placenta iphetha ukwakheka kwayo. Manje unesibopho ngokugcwele ekuthuthukiseni i-fetus, okhiqiza inani elifanele lama hormone we-estrogen ne-progesterone. Ubukhulu be-placenta bungaba ngu-16 mm. Kuyisivimbela kanzima ezintweni ezihlukahlukene eziyingozi, kodwa ngesikhathi esifanayo sidlula ngama-carbohydrate, amafutha kanye namaprotheni adingekayo kumntwana.
Usayizi we-Fetal ngesonto 13 lokukhulelwa
Isithelo emavikini angu-13 sinesisindo esingaba ngu-15 - 25 g nesayizi ka-7 kuya ku-8 cm. Inhliziyo yalesi sidalwa esincane ngosuku isiphumelele amalitha angu-23 egazi. Ekupheleni kwamasonto angu-13-14 izithelo ziyoba nobude buka-10-12 cm, isisindo esingu-20-30 g, kanye nobubanzi bekhanda cishe ngo-3 cm.
Ukuthuthukiswa kwezitho zesisu kanye nezinhlelo ezontweni zesonto lesishiyagalolunye kuya ku-14 lokukhulelwa
Iqala ngokujulile ukuthuthukiswa kobuchopho. I-reflexes ivela: isiponji somntwana siphendukekile, izandla zicindezelwa zibe yizintambo, zingaqala, i-grimace, zidonsa iminwe emlonyeni. Esikhathini esithile isithelo sithemba kakhulu, kodwa isikhathi esiningi silala.
Isikhumba esicindezelekile nesesisa somntwana siyaqhubeka sikhula, kusenayo izicubu ezinamafutha angaphansi komhlaba, ngakho isikhumba saso sibomvu futhi sibomvu nemithambo encane yegazi ebonakala phezulu.
Ukwakhiwa kwesistimu yethambo kuqhubekela phambili. Emasontweni angama-13, ingane ivele isine-gland eyakhiwe ngokwanele, ngenxa yokuthi i-calcium ibeka emathanjeni. Amathambo emilenze kancane kancane aqhubeka isikhathi eside, inqubo yokwehliswa kwe-skull namathambo omgogodla uqala, izimbambo zokuqala zivela, ukuqala kwamazinyo angama-amabili e- milk .
I-fetus evikini lesishiyagalombili lokukhulelwa nayo inehlelo lokuphefumula okwenziwe kahle. Ingane iphefumula. Uma ingane iqala ukuhlupheka ngenxa yokuntuleka kwe-oxygen, ezinye ze-amniotic fluid zingena emaphashini.
Ngalesi sikhathi i-prostate gland iqala ukukhula kubafana. Amantombazane akhula ama-germ cells. Izitho zobulili ziyaqhubeka zihlukanisa ngokuphindaphindiwe: isifo sofuba siba sikhatsi eside futhi kancane kancane siphenduka singene e-penis noma singene kwi-clitoris, sibheke phansi. Ngakho-ke, izakhi zofuzo zangaphandle zakhiwa ngokwanele ukuze zihlukanise intombazane evela kumfana.
Emathunjini omntwana kukhona i-villi, edlala indima ebalulekile ekugubheni nasekukhuthazeni ukudla. Amangqamuzana egazi aqala ukwakha esibindi, emnkantsheni wezinsana, kanye nesilwane se-fetus. Ukuthuthukiswa kwezinxenye zokuqala ze-insulin kuqala nge-pancreas. Umshini wezwi lomntwana uqala ukudalwa.
Umqondo wephunga uqala - ingane ibamba iphunga futhi inambitheka ukudla okushiwo umama wayo. Akuwona wonke umama womama ongathanda ukumthanda, futhi uthanda izitsha ezithile ngokukhethekile. Ososayensi bathole ukuthi uma owesifazane emva kokubeletha kushintsha kakhulu ukudla, kungaholela ezinkingeni ezithile ekunceliseni ingane, ngoba umntwana uhlala ecabanga ngephunga elizwakalayo emntwaneni.
Ngokuqondene nokubonakala kwemvuthu, ekugcineni ithola izici eziningi ezicacile. Ikhanda le-fetus alisayikucindezela ngokumelene nesifuba, ibhuloho lempumlo, ama-arches superciliary, ne-chinyane zichazwe ngokucacile. Izindlebe zisendaweni yazo evamile. Amehlo athelelana, kepha namanje ahlanganiswe namajwabu amisiwe.
Iningi lomsebenzi ekubekeni izitho eziyisisekelo kanye nezinhlelo zomzimba sezivele zenziwe, sekuyisikhathi sokwakheka kwesimo somzwelo. Ngalesi sikhathi, ingane ilalela njalo futhi iqala ukusabela ngezibonakaliso ezivela ezweni langaphandle (elibandayo, elifudumele, elimnyama, elikhanyayo, umsindo, othinta), ukuqonda amakhono amasha.