Njengomthetho, kunokuba kunzima ukuphawula xa iqanda lixiliswa, ngoko ukuqala kokukhulelwa kuqala ukubala ukususela kumhla wokuqala komjikelezo wokugqibela wesigxina.
Umquba
Ukususela ngeli xesha liqala ukubunjwa kunye nokuvuthwa okulandelayo kweqanda. Ukuchumisa kwakhe kubakho kwiiveki ezimbini ukuya kweyesibini.
Ngaphambi kokuba iifestile zokuzala zesilisa nezesetyhini zihlangane, kuya kuthatha iiyure ezingama-3 ukuya ku-6. I-spermatozoa eninzi, ehamba kwiqanda, idibana nendlela yabo ininzi yemingcipheko, ngenxa yoko, i-spermatozoa enamandla kunazo zonke ifikelela kwiinjongo. Kodwa omnye wabo uya kuthatha inxaxheba kwinkqubo yokuchumisa.
Xa i-spermatozoon igqithisa isambatho seqanda, ngokukhawuleza umzimba womfazi uqala ukwakhiwa komsebenzi wayo, ngoku uya kuhloswa ukugcina ukukhulelwa.
Kwinkqubo yokuchumisa, iseli elitsha kunye nekhowudi yayo yofuzo, eya kugqiba ngesondo somntwana, ukuma kwayo kweendlebe, umbala wamehlo kunye nezinye izinto, kubunjwa kwiiseli zabazali ababini, ngasinye sinesiqingatha seethaphu ze-chromosomes nganye.
Ngomhla wesi-4 ukuya kwe-5, iqanda elichumayo lifikelela kwisibeleko. Ngalesi sikhathi, sele sele ikhulile ibe ngumbungu onama-cell cell.
Ukufakelwa kwindonga yesisu kuvela ekuqaleni kweveki yesithathu. Emva kokuba le mithi igqityiwe. Ukuhambela kwisibeleko kunye nokuqhotyosheliswa eludongeni kwinqanaba eliyingozi kakhulu lokuphuhliswa kwentombazana ngenyanga yokuqala.
Ukuqalwa komntwana
Ngenyanga yokuqala emva kokuphela kwenkqubo yokumisela, ukuqala kokomntwana okusebenzayo kuqala. I-chorion iqala-i-placenta ezayo, i-amnion-isandulela se-fetal bladder kunye nentambo ye-umbilical. Ukuphuhliswa kwe-fetus ngenyanga yokuqala yokukhulelwa kuqala ngokuqulunqwa kwamaphephancwadi amathathu. Ngamnye wabo umele umbungu wezitho ezihlukeneyo kunye nezicubu.
- Iqabunga langaphandle le-embryonic lihlaziywa yinkqubo yenzwa, amazinyo, isikhumba, iindlebe, i-epithelium yamehlo, impumlo, izipikili kunye neenwele.
- Iqabunga elincinci lentsholongwane lisebenza njengesiseko (imisipha yamathambo, izitho zangaphakathi, umgudu, i-cartilage, iinqanawa, igazi, i-lymph, i-glands).
- Iqabunga langaphakathi le-embryonic lisebenza njengesiseko sokwakheka kwimbumba yokuphefumula, izitho zesisu esiswini, isibindi kunye ne-pancreas.
Ekupheleni kwinyanga e-1 yokukhulelwa, i-fetus (embryo) isele ibe nobude be-1 mm (imbungu ibonakala kwiso iso). Kukho ibhukumaka ye-chord-i-future spine. Kukho ibhukumaka yenhliziyo kunye nokubonakala kweemitha zokuqala zegazi.