Layers lwegciwane: Iintlobo zabo kunye neempawu zolwakhiwo

maleko lwegciwane - gama jikelele embryology. Bona Zimiseleni imaleko umzimba Umbungu kwi kumabakala okuqala zophuhliso osandul. Kwiimeko ezininzi, ezi Ingaphandle epithelial ngokwendalo.

maleko lwegciwane lokuhlela kwiintlobo ezintathu:

• ectoderm - umaleko engaphandle, leyo nangoku ibizwa igama epiblast, okanye ulusu-onovakalelo umaleko;

• endoderm - umaleko engaphakathi iiseli. Kananjalo oku kubizwa ngokuba hypoblast ama okanye iphepha glandular;

• umaleko eliphakathi (mesoderm okanye mezoblast).

layers lwegciwane (ngokuxhomekeke kwindawo zabo luphawulwa iimpawu ezithile iiseli. Ngoko ke, umaleko olungaphandle umbungu ubunjwe weseli eliqaqambileyo eziphakamileyo kubume bayo efana epithelium columnar. Imakhishithi ngaphakathi iqulathe kwiimeko ezininzi iiseli ezinkulu bazaliswe ziiplatelets sac ethile. banalo imbonakalo atshabalalisa olwenza ukuba khangela ngathi epithelium carcinomas.

Mesoderm kwinqanaba lokuqala osimelela ngentonga kunye stellate iiseli. Baqhubeka zakha umaleko epithelial. Kufuneka ke ukuba abaphandi abaninzi bakholelwa ukuba mesoderm - lo maleko yintsholongwane avareji, engeyiyo yona iiseli ndawo elizimeleyo.

sheets osandul lokuqala kufuneka indlela ukuma basemgongxweni, leyo kuthiwa sitho blastodermal. Kwenye nezibonda zayo uya iqela leeseli, eyaziwa ngokuba cell abaninzi. Inika ekuchithekeni colon ephambili (endoderm).

Kufuneka ke ukuba la maqumrhu ezahlukeneyo akhiwa ngoomaleko osandul. Ngoko ke, nanku luvo ukusuka ectoderm, ityhubhu yokwetyisa kuqala endoderm, amathambo, inkqubo yokujikeleza kunye nezihlunu sivela mesoderm.

Kufuneka kuqatshelwe ukuba inwebu ethile osandul 'ukusekwa ngexesha embryogenesis. Ba okwethutyana, musa inxaxheba kukwenziwa amalungu kunye abakho kuphela ngexesha kuphuhliso osandul. Iklasi nganye of eziphilayo ingalandwa iinkalo ezithile ukusekwa kunye nolwakhiwo amaqokobhe lwe data.

Ngophuhliso embryology baqalisa ukukhangela ukufana imibungu, leyo ochazwe kuqala KM Baer ngo 1828. Kamva, Charles Darwin ezichongiweyo ingcambu unobangela Ukufana Amadlozi zonke izinto - imvelaphi yabo eqhelekileyo. Severs Kwakhona uthi neempawu ezixhaphakileyo zinxulunyaniswa nasekusungulweni imibungu kwenzeka anaboly kwiimeko ezininzi.

Xa kuthelekiswa izigaba ezingundoqo kuphuhliso lwe sisihluma kwiiklasi ezahlukeneyo kunye neentlobo zezilwanyana ziye zafunyanwa iimpawu ezithile ukuba ukuqulunqa umthetho ukufana osandul. Izibonelelo iphambili yalo mthetho kukuba iintsholongwane ze eziphilayo zohlobo olufanayo xa nisaqala yophuhliso lwayo ziyafana kakhulu. Kamva, umbungu luphawulwa iimpawu ngamnye ngakumbi abonisa ukuba ekuso sodidi efanelekileyo kunye neentlobo. Ngelo xesha abameli iintsholongwane zohlobo olufanayo nalapha ngaphakatyhi yahlukanisiwe ukusuka kwenye nenye, kunye nokufana lwabo lokuqala ayisa waphawula.