Neurula - siteji ya chitukuko Ndisanaumbidwe

Imodzi mwa nthawi za chitukuko munthu wa zamoyo - ontogenesis ndi embryogenesis. Pamafunikanso nthawi kuyambira chiyambi cha mapangidwe zygote musanakhale kubadwa lake ndi tichipeza magawo angapo successively akudutsa. Mmodzi wa iwo ndi neurula. Izi siteji ya chitukuko cha inakhala, imbaenda kuna mapangidwe wosabadwayo, kukhala zigawo nyongolosi atatu, komanso chubu ubongo. Ndiponso, kwa masabata angapo Ndisanaumbidwe ndi anapangidwa wa chachikulu structural zinthu zonse za dongosolo chapakati ndi zotumphukira mantha. M'nkhani ino tikambirana mbali ya gawo komanso ndondomeko zokhudza thupi zikuchitika mu izo.

Magawo chitukuko embryonic

Full ndi yunifolomu onongani zygote placental nyama, monga anthu, tidzapeza dongosolo kuti amaoneka ngati mabulosi mabulosi kapena rasipiberi. Iwo akutchedwa morula. Ndiye maselo ake anakonza mu mzere umodzi, ndipo anapanga blastula. Izi thumba dzenje, makoma amene anapanga blastomeres-maselo. Kenako, ndondomeko invagination, chifukwa mu maonekedwe a wosanjikiza awiri a mwana wosabadwayo lapansi. Ichi ndi gawo gastrula. Amakhala ectoderm ndi endoderm, ndipo ali ndi pakamwa chachikulu, wotchedwa Mlomo wa blastopore lapansi. Kenako m'mbali ndi chatsekedwa, ndi mwana wosabadwayo ali maonekedwe a wosanjikiza awiri thumba. zosokonezeka wotsatira mu dongosolo Ndisanaumbidwe zokhudza maonekedwe a wina, wachitatu, wosanjikiza germinal - mesoderm atagona pakati pa ecto- ndi endoderm. maphunziro ake ku embryogenesis anthu ali limatchula zake. Tidzaphunzira mwatsatanetsatane.

mapangidwe mesenchyme

Mluza mu M'mimbamo mtundu olekanitsidwa njira lateral - somites kapena matumba. Iwo anachokera ku wosazindikira m'matumbo khoma. Kuchokera mesoderm kukhala ndi somites ali ngati chizindikiro kwa organogenesis pamwamba. Anapanga dongosolo la nyumba zofunika kwambiri: notochord, matumbo ndi chubu ubongo. Iwo amatchedwa ziwalo ofananira. Nyongolosi ya complicating matabwa ake, kupanga msinkhu - neurula. Izo zikuchitika pa 3 - masabata 4 mimba. Limagwirira la mapangidwe anati apamwamba Ndisanaumbidwe siteji zambiri zokhudza nkhani.

Monga Ndisanaumbidwe limapezeka chubu ubongo

Lakunja pepala germinal - ectoderm, kumbali dorsal wa mwana wosabadwayo umakhala wandiweyani wakuda, ndipo n'kukhala mbale ubongo. m'mbali ake aukitsidwa, kupanga odzigudubuza awiri. Pakati pawo pali kudzera m'njira, kenako yosintha kuti patsekeke a ubongo ndi msana wodzazidwa ndi mowa. Ubongo mbale atseka m'mbali ake, choyamba mu dera khomo lachiberekero wa mwana wosabadwayo, ndi mwana wosabadwayo ndiyeno nkubwerera pamodzi olamulira thupi. Ikutha ndi kutsekedwa kwa mbale ubongo mu gawo cranial komwe ubongo osauka vesicles - zoyambira za ubongo. Ndi masabata 4 mimba, chubu ubongo kwathunthu popeleka ma kuchokera ectoderm lapansi. Chifukwa chubu ubongo anapanga maselo mitsempha ndi minofu trophic - kumachitika neurula ndi neuroglia. Izi siteji ya chitukuko embryonic, chomwe zigawo nyongolosi atatu ndi chubu ubongo. Kodi ku izo anapanga mantha dongosolo anthu?

Ntchito ya ubongo Crest lomenyera wamanjenje dongosolo

Chikadzangotha odzigudubuza kujowina ndi maonekedwe a chubu ubongo mu zigawo chapakati ndi cutaneous ectoderm kupatukana gulu la maselo. Ndi ili m'mbali olamulira a Ndisanaumbidwe thupi pakati wosanjikiza lakunja ndi embryonic chubu ubongo amatchedwa Crest ubongo. zanyengo ma ndi mbali yapadera. Izi - amatha m'madera osiyanasiyana Ndisanaumbidwe anthu. Mwachitsanzo, ena mwa maselo a kathupi mkatikati mwa thupi ndipo neurocytes mawonekedwe ndi neuroglia ganglia magulu wachifundo ndi parasympathetic a mbali zotumphukira ya ubongo. maselo ena kukhala Crest ubongo, poyamba n'kupanga ganglion mbale, amene ndiye lidzasinthidwa mfundo awiriawiri 31 misempha msana. Mu ichi neurulation ndondomeko osati kutha ndipo pali kusintha zina ndi mbali ya dongosolo chapakati ndi zotumphukira mantha.

Kuchuluka kuchulukitsa kwa kapangidwe ka Ndisanaumbidwe pa siteji neurula

Kusamuka maselo ubongo Crest, kuyambira gawo wapakatikati pafupi ndi zigawo sacral chingwe pa 27 - 28 somites, angathe kusiyanitsa, kuti makamaka zofanana polustvolovym maselo a mafupa. Kuyambira gawo lotsatira la diencephalon kwa sacral khadi Ndisanaumbidwe pa 27 - 28 somite awiriawiri, mapangidwe neurocytes okhwima ndi maselo glial wa misempha cranial ndi ganglia ya zida Makutu ndi vestibular. Pa nthawi imeneyi chitukuko embryonic mu osiyanasiyana kuchokera 1 mpaka 7 somite opangidwa kuchokera ku Crest kuyambitsa mapangidwe ganglia autonomic innervating mtima, mapapo, matumbo ndi ziwalo za mafupa a chiuno wosabadwayo. Malizitsani kusasitsa ya ubongo ndi kwa masabata 40 a mimba.

The zifukwa kusamuka maselo ubongo Crest

Zochokera pamwamba njira zafotokozedwa ya ubongo, funso zachilengedwe lakuti: Kodi mungafotokoze chifukwa anasamutsa ubongo maselo Crest pa maulendo ataliatali mu thupi la mwana wosabadwayo? Modern embryology anafotokoza iwo motere. Choyamba, neurula - siteji ya embryogenesis omwe ubongo maselo Crest kutaya luso lawo kutsatira, mwachitsanzo kulankhulana wina ndi mzake ... Chifukwa chachiwiri lagona mipweya ya masanjidwewo extracellular wa mwana wosabadwayo ndi. Iwo wapangidwa ndi asidi hyaluronic ndi mapuloteni: kolajeni, laminin, fibronectin ndi tropism maselo ubongo Crest.

ubwenzi wawo ndi masanjidwewo extracellular ndi kusamuka kumachitika chifukwa posonyeza mamolekyulu - integrins, komanso pamaso pa somites neurula glycoproteins lapadera: tenascin ndi T-cadherin. Zonsezi zipangitsa chitukuko cha mbali yaikulu ya ubongo wa mwana wosabadwayo ndi.