Izigaba zokuthuthukiswa kwamabriyoni

Inqubo yokuthuthukiswa kwamabriyoni yomuntu inezinyathelo ezine, futhi isikhathi sithatha amasonto angu-8. Iqala ngomhlangano wamaseli wesilisa nabesilisa besini, ukuhlanganiswa kwawo kanye nokubunjwa kwe-zygote, futhi iphetha ngokubunjwa kwe-embryo.

Ziyini izigaba ze-embryogenesis?

Emva kokuhlanganiswa kwe-spermatozoon neqanda, i- zygote yenziwa . Kungakapheli izinsuku ezingu-3-4 zihamba ngezinyawo zamathambo futhi zifinyelela emgodini wesibindi. Kulokhu, isikhathi sokuchoboza sibonakala . Ibonakala ngokuhlukaniswa kwamaseli okunamandla okuqinile. Ekupheleni kwalesi sigaba sokuthuthukiswa kombungu , i-blastula ikhiwa - iqoqo le-blastomeres ngayinye, ngendlela yebhola.

Isikhathi sesithathu, ukugcoba, kuhilela ukwakhiwa kweqabunga lesibili lokubumbana, okuholela ekwakheni i-gastrula. Emva kwalokhu, ihlumela lesithathu lokuhluma livela - i-mesoderm. Ngokungafani nama-vertebrates, i-embryogenesis emuntwini inzima ngokuthuthukiswa kwezinto eziyinkimbinkimbi ze-axial - ama-rudiments wesimiso sezinzwa, kanye nama-axial skeleton futhi, kanye nayo, imisundu isethwe.

Esigabeni sesine sokuthuthukiswa kombungu womuntu, izakhi zamalungu esizayo kanye nezinhlelo ezakhelwe kulo mzuzu zihlukaniswe. Ngakho-ke, isimiso sezinzwa esishiwo ngenhla sakhiwa kusuka eqabeni lokuqala le-embryonic, kanti ezinye izingxenye zomqondo. Kusukela ku-endoderm yesibili, izicubu ze-epithelial ezifaka umsele wokugaya kanye nezigulane ezikuwo zikhona. I-mesenchyme yakha i-connectif, i-cartilaginous, i-bone tishu, kanye nesistimu ye-vascular.

Ngenxa yalokho ukulandelana kwalezi zigaba kungadilizwa kanjani?

Izigaba zokuthuthukiswa kwamabriyoni, ezethulwa etafuleni elingezansi, azihambi njalo ngendlela okudingeka ngayo. Ngakho-ke, ngaphansi kwethonya lezici ezithile, ikakhulukazi ezingavamile, inkambo yokuthuthukiswa kwezitho kanye nezinhlelo ezithile zingaphazanyiswa. Phakathi kwezizathu ezinjalo singahlukanisa:

• ukwephulwa kwezimo zemvelo (izinga lokushisa, ukhemikhali, njll);
• ukwephula ukuxhumana phakathi kwamangqamuzana ngabanye;
• ukuzalwa.

Lokhu akuzona zonke izizathu eziholela ekuphukeni kokuthuthukiswa kombungu. Kuningi labo ukuthi ngezinye izikhathi odokotela abakwazi ukukhomba kahle ukuthi yini eyenza inqubo yokuthuthukiswa kwe-embryon ihluleke esimweni esithile. Ngenxa yokuthi izigaba zokuthuthukiswa kombungu wesintu zihlukumeza ukulandelana kwazo, izimo eziphuthumayo zenzeka, ezinye zazo zingaholela ekufeni kombungu.