Amapheshana e-Embryonic: izinhlobo zawo nezici zesakhiwo

Amaqabunga e-Germinal yiyona nkulumo esemqoka embryology. Zibonisa izingxenye zomzimba wesisu ekuqaleni kokuthuthukiswa kwamabriyoni. Ezimweni eziningi, lezi zendlalelo zi-epithelial.

Amapheshana e-embryonic ahlukaniswa abe izinhlobo ezintathu:

• i-ectoderm - iqabunga elingaphandle, elibizwa ngokuthi i-epiblast noma isendlalelo esibucayi;

• endoderm - ungqimba lwangaphakathi lwamaseli. Kungabizwa nangokuthi i-hypoblast noma ishidi lokunyundezela ngaphakathi;

• Ungqimba oluphakathi (mesoderm noma mesoblast).

I-embryo ishiya (kuye ngokuthi indawo yayo, ibonakala ngezici eziqondile zamaseli: isibonelo, ungqimba lwangaphandle lwe-embryo liqukethe amangqamuzana alula futhi amade, esakhiweni sawo afana ne-epithelium ye-cylindrical. Iqabunga elingaphakathi linama-cell amaningi amakhulu agcwele amacwecwe e-yolk. Zibukeka kahle, okwenza zibukeke njenge- epithelium flat.

I-mesoderm esiteji sokuqala iqukethe amangqamuzana afana namagundane. Bese benza isendlalelo se-epithelial. Kumelwe ngitshele ukuthi abacwaningi abaningi bakholelwa ukuthi i-mesoderm iyiqabunga eliphakathi kwamabrionic elingelona uhlaka oluzimele lwamaseli.

Amashidi e-embryonic aqale abe nesimo sesakhiwo esingenalutho, esibizwa nge-blastodermal vesicle. Kwesinye sezibonda zayo iqembu lamaseli lihlangene, elibizwa ngokuthi isisindo samangqamuzana. Iphakamisa igundane eliyisisekelo (endoderm).

Kumele kuthiwa izitho ezihlukene zakhiwe ngamashidi e-embryonic. Ngakho-ke, isimiso sezinzwa sisuka ku-ectoderm, ithubhu yokugaya iqala kusukela ku-endoderm, kanye namasipha, isimiso sokujikeleza, kanye nemisipha iphuma kumesoderm.

Kumele kuqashelwe ukuthi embryogenesis, izinambuzane ezikhethekile zamabriyoni zenziwa. Besikhashana, ungabambi iqhaza ekubunjweni kwezitho futhi ukhona kuphela ngesikhathi sokuthuthukiswa kwamabriyoni. Isigaba ngasinye sezinto eziphilayo sithola izinto ezithile ekubunjweni nasekuhleleni kwalezi zigobolondo.

Ngokuthuthukiswa kwe-embryology kwaqala ukucacisa ukufana kwemibungu, eyayihlongozwa okokuqala nguK. I-Baer ngonyaka ka-1828. Ngemva kwesikhashana, uCharles Darwin wachaza isizathu esiyinhloko sokufaniswa kwemibungu yazo zonke izilwane - umthombo wazo ovamile. U-Severov uphinde wathi izibonakaliso ezivamile zemibungu zihlobene nokuziphendukela kwemvelo, okwenzeka ezimweni eziningi ngokusebenzisa i-anabolism.

Uma kuqhathaniswa izigaba eziyinhloko zokuthuthukiswa kwemibungu yamakilasi ahlukahlukene kanye nezinhlobo zezilwane, kunezinto ezithile ezitholakalayo ezasisiza ukuba senze umthetho wokufaniswa kwe-embryonic. Izinhlinzeko ezisemqoka zalomthetho wukuthi ama-germs ezinhlobo zenye uhlobo ezinyathelweni zakuqala zentuthuko yazo zifana kakhulu. Ngemva kwalokho, umbungu ubonakala ngezici ezizimele ezibonisa ukuthi ziyingxenye yezinhlobo nezinhlobo ezihambisanayo. Kulesi simo, imibungu yabamele uhlobo olulodwa iyahlukana kakhulu, kanti ukufana kwabo okuyisisekelo akusekho okulandelanayo.