Nyongolosi zigawo: mitundu ndi mbali structural

zigawo nyongolosi - kazembe yaitali embryology. Iwo tisonyezeni zigawo wosabadwa thupi pa siteji oyambirira a chitukuko embryonic. Nthawi zambiri, zigawo izi ndi zaminyewa m'chilengedwe.

zigawo nyongolosi kuti m'kagulu mu mitundu itatu:

• ectoderm - wosanjikiza akunja, limene lili ndi dzina la epiblast, kapena khungu tcheru wosanjikiza;

• endoderm - ndi M'kati mwa maselo. Angagwiritsidwenso otchedwa enteric hypoblast kapena glandular pepala;

• wosanjikiza pakati (mesoderm kapena mezoblast).

zigawo nyongolosi (malingana ndi malo awo yodziwika ndi mbali zina za maselo. Choncho wosanjikiza kunja kwa mwana wosabadwayo ndi wapangidwa ndi selo yowala ndi mkulu imene matabwa ake ofanana epithelium columnar. The pepala mkati imakhala nthawi zambiri maselo lalikulu ndizodzazidwa ndi maselo othandiza magazi kuundana yeniyeni yolk. ali ndi flattened maonekedwe zimawachititsa kuyang'ana ngati epithelium squamous.

Mesoderm pa siteji yoyamba imakhala maselo ndi spindle ndi stellate. Iwo anapitiriza kupanga wosanjikiza zaminyewa. Izo ziyenera kuti Ofufuza ambiri amakhulupirira kuti mesoderm - ndi pafupifupi nyongolosi zigawo, zimene siziri palokha maselo posungira.

Embryonic mapepala oyamba ndi maonekedwe a mapangidwe dzenje, amene amatchulidwa blastodermal vesicle. Pa limodzi la mitengo yake yonyamulira ati gulu maselo, lotchedwa misa selo. Izo zinagwira m'matumbo chachikulu (endoderm).

Izo ziyenera kuti matupi osiyanasiyana anapanga ku zigawo embryonic. Choncho mantha dongosolo auka kwa ectoderm, ndi chubu m'mimba akuyamba ku endoderm, ndi mafupa, mitsempha ya magazi ndi minofu tinachokera kwa mesoderm lapansi.

Iwo ayenera kukumbukira kuti yeniyeni nembanemba embryonic inakhazikitsidwa m'zaka embryogenesis. Kalekale, samenya nawo mapangidwe ziwalo ndi unalipo pa chitukuko embryonic. Lililonse kalasi ya zamoyo unkagwiritsidwa mbali zina mu mapangidwe ndi dongosolo la zipolopolo deta.

Ndi chitukuko cha embryology anayamba kudziwa kufanana kwa mazira, amene anafotokozedwa koyamba Km Baer mu 1828. Patapita kanthawi, Charles Darwin kuzindikiridwa chimayambitsa kufanana kwa mazira wa zamoyo zonse - anachokera wamba. Severs ankanena kuti zizindikiro zosonyeza imakhudzana ndi zamoyo wa mazira amene amapezeka nthawi zambiri ndi anaboly.

Pamene akuyerekeza zigawo zikuluzikulu chitukuko cha mazira a magulu osiyanasiyana ndipo mitundu ya nyama apezeka makhalidwe ena amene amaloledwa zopanga lamulo kufanana embryonic. The chakudya chachikulu a chilamulo ichi ndi majeremusi ya zinthu za mtundu womwewo mu magawo oyambirira a chitukuko ndi ofanana kwambiri. Kenako, mwana wosabadwayo ndi amakhala ndi zinthu zambiri munthu amene amasonyeza kuti adzaupereka kwa mtundu zogwirizana ndi mitundu. Pa nthawi yomweyo oimira majeremusi a mtundu womwewo ambiri anapatukana, ndi kufanana yaikulu salinso anati.