Inkathi ye-embryogenesis, okungukuthi, lapho umbungu uqala futhi ukhula, uhlala kusukela osukwini lokuqala ukuya kwesonto lama-11 kuya kweyishumi nambili lokukhulelwa. Emva kwalesi sikhathi, umbungu usuvele ubizwa ngokuthi i-fetus. Kulesi simo, usuku lokuqala lokuya esikhathini sokugcina lithathwa njengengxenye yokuqala.
Ukuthuthukiswa kwempilo emisha kuqala ngesikhatsi lapho i-ovum isifazane ikhulelwa khona . Uma i-spermatozoon ne-ovum ihlangana, i-zygote yakha, eqala ukuhlukanisa ngamahora angu-26-30 futhi yenza ama-embroidery amaningi, ubukhulu babo, njengoba besho, banda ngokukhipha imifino nemingcele.
Uma ezinsukwini ezine zokuqala zikhona, i-embryo inesilinganiso sobukhulu buka-0.14 mm, kanti ngosuku lwesithupha lifinyelela ku-0.2 mm, futhi ekupheleni kwe-7 kuya kwangu-0.3 mm.
Ngelanga 7-8, umbungu usungulwe emdongeni wesibeletho.
Ngosuku lwe-12 lokuthuthukiswa, ubukhulu bombungu kakade buyi-2 mm.
Shintsha usayizi we-embryo ngesonto lokukhulelwa
- ngeviki lesithathu lokuthuthukiswa kombungu, okungukuthi, ngeviki lesihlanu lokukhulelwa, i-ectoderm esakhiweni somgogodla wesikhathi esizayo wengane yenza i-groove. Khona-ke imiphetho yayo ivaliwe futhi kuhlanganiswa ithebhu ye-neural - i-dorsal kanye nobuchopho esikhathini esizayo. Ekupheleni kwaleli sonto, umbungu ufinyelela ku-4 mm;
- Ngeviki lesine, isimiso sezinzwa esiyinhloko sakhiwe kusuka ku-tube ye-neural - i-dorsal kanye nobuchopho. Inhliziyo yenza ukuphika kwayo kokuqala. Ukubukeka kwemilenze, izandla, amehlo nezitho zangaphakathi, kuqala ukugeleza igazi emifuleni yegazi;
- emasontweni ama-5-6, i-head and facial features of the embryo zakhiwa. Ubude bayo buyingxenye ye-1 cm
- Ngeviki 7 izinyathelo zihlanganisa futhi ziqale ukwakha amaphaphu. Inhliziyo ephelele. Ubukhulu bombungu buyi-1.5 cm;
- emavikini ayisishiyagalombili zonke izitho ezibalulekile zenziwa. Ubukhulu bombungu buyi- 2 cm;
- emavikini ayisishiyagalolunye ama-ear, ama-nose, amajwabu amehlo, umlomo, amehlo. Ukuphakama kwengane kungaba ngu-3 cm futhi iyaqhubeka ikhula ngokushesha;
- emasontweni ayishumi, okungukuthi, emasontweni angu-12 okukhulelwa, isakhiwo samathambo sihambisana ngqo nomuntu. Izitho zinde. Igazi lomntwana lithola iqembu lalo. Ubungako bombungu, obusha manje buba yisimo se-fetal, ungafinyelela ku-7 cm.
Ukwandiswa ngobukhulu bombungu kungalandelwa ngokusho kwetafula elingezansi.