Ukuchithwa kwe-zygote

Umqondo "wokuzalwa komuntu omusha", njengombuso, unqunyelwe kuphela yizinhlangano mayelana nokukhulelwa kwengane ngenxa yomhlangano okhuthele weqanda nesidoda. Ngaphezu kwalokho, ngokusho kweningi, ukukhulelwa kwenzeka, i-fetus ikhula futhi isisu esikhulu sikhula kumama ozayo. Yini okumele ihlakaniphe, yonke into iyinto elula ... Empeleni, ukuthuthukiswa kokubeletha komuntu kuyinkimbinkimbi ebaluleke kakhulu futhi eyinkimbinkimbi, edinga ukutadisha ngokujulile. Ake sizame ukuqonda ubuqili besinye sezigaba zayo - ukuhlukaniswa kwe-zygote.

I-Zygote iyi-sperm ovum. Kuwukukhulelwa, okungenzeka kungakapheli izinsuku ezintathu emva kocansi, ukuthuthukiswa kwe-intrauterine komuntu kuqala. Ngenxa yokungena kwe-spermatozoon eqenjini, i-nuclei yabo ihlangene namaqoqo e-chromosomal yama-chromosomes omama angu-23 nobaba abangu-23 futhi i-nucleus yenziwa lonke isethi yama-chromosomes angama-46 avela kuwo wonke amaseli omzimba, ngaphandle kwamaseli omzimba. Emva kwalokhu, i-zygote ichotshoziwe.

Ukuhlukaniswa kwe-zygote yomuntu kuyindlela yokwenza izinsuku ezingu-3-4 zokuhlukanisa umbungu zibe izingxenye ezincane zeseli ngokukhiqiza isakhiwo sazo ngendlela efana nesakhiwo se-cell cell (i-mitosis noma i-fission ngohlobo lwe-cloning) ngenkathi igcina ubukhulu bayo (cishe 130 μm). Ama-blastomers - amangqamuzana akhiwa ngesikhathi sokuhlukaniswa kwe-zygote, ahlukana futhi, ngamazinga ahlukene, ngamanye amazwi, ukwahlukana kwabo akuhambisani.

Ngenxa yesigaba sokuqala se-zygote, kunezinhlobo ezimbili ze-blastomeres ezihlukanisiwe. Enye, enkulu, "emnyama", isisekelo sokuthuthukiswa kwezicubu nezitho zombungu. Iqoqo lama-blastomeres amakhulu atholakala ngezigaba ezilandelayo libizwa ngokuthi i-embryoblast. Uhlobo lwesibili, oluncane noluthi "olukhanyayo" lwe-blastomer, ukuhlukaniswa okwenzeka ngokushesha, kudala isethi efanayo - i-trophoblast. Ngesizo saso kunamakholi afana nomunwe, okudingekayo ukuze kube nokulungiswa okulandelayo kwe-zygote kuya emgodini wesibindi. I-Blastomeres, ngaphandle kokuxhumana nomunye nomunye, ibanjwe ngosizo lwegobolondo elikhazimulayo leqanda kuphela. Ukuphuka kwawo kungaholela ekwakhiweni kwemibungu efana nezakhi zofuzo, isibonelo, amawele afanayo.

Ukubonakala kombungu wezinhlobonhlobo

Ngenxa yokuhlukaniswa kwe-zygote, i-embryo enezinhlobonhlobo zakhiwe, ezihlanganisa izingqimba zamangqamuzana ze-embryoblast (ngaphakathi) kanye ne-trophoblast (i-periphery). Lesi yisiteji se-morula - isikhathi sokuthuthukiswa kwamabriyoni, lapho kunezinhlamvu ezingamakhulu ayisishiyagalolunye ehlathini, ukuchoboza ukwakheka okwenzeka lapho umbungu uhamba eduze kwe-oviduct emgodini wesibeletho. Ngenxa yokuntuleka kokuhamba okuzimele, ukuhamba kweqanda elichotshoziwe kwenzeka ngaphansi kwamathonya ama-hormone we-progesterone ne-estrogen ngenxa ye-peristaltic musculature ye-oviduct, ukuhamba kwe-cilia ye-epithelium yayo, kanye nokuhamba kwezingcingo ezisegulini. Kwesinye isikhathi ngosuku lwesithupha emva kokukhulelwa, ukuthola i-morula ngaphakathi kwesibeletho kuholela ekuqaleni kwenqubo ye-blastulation - ukwakheka kwe-blastocyst, okuyi-vial engenalutho egcwala uketshezi oluvela emaceleni athuthukile we-trophoblast ne-embryoblast.

Cishe ngosuku lweshumi nesishiyagalolunye-10, umbungu (ukufakwa komfutho) we-embryo ukhula udongeni lwesisu, esivele sisesimweni esiphelele samaseli awo. Kusukela kulo mzuzu owesifazane uyeka umjikelezo wokuya esikhathini, futhi ungakwazi ukunquma ukuqala kokukhulelwa.