Ectoderm - lo maleko imbewu yangaphandle

Le ectoderm yinxalenye nasiphi ephilayo multicellular isilwanyana. eminye kuphela nje zinamaqoqo igcinwa kuphela ngexesha kuphuhliso osandul, ngoxa abanye - yobomi. Yintoni ectoderm?

Types of layers lwegciwane

Ngexesha ontogeny beqanda aqhamileyo iyahlula ngokuphindaphindiweyo, ukwakha kwiiseli ezininzi ekuhambeni kwexesha. Ngexesha kwentlobo sabo ukuyilwa kwiiseli ezininzi umzimba, leyo kamva aya kuba kwinyama, amalungu kunye neenkqubo. Ectoderm - iqhekeza elo germinal engaphandle. Ngexesha uphuhliso elilodwa ukuba abunjwe ngumntu wokuqala maleko ongaphandle iiseli. Igqabi engaphakathi umbungu ekuthiwa endoderm. Kamva Kwathi ukususela kwiinkqubo bokuphefumla esiswini. Ukususela phakathi lwegciwane umaleko - imizimba kwakheka abonakala ukubopha kunye umzimba wonke - mesoderm. Yeyona izihlunu kunye nemisipha, amathambo lwangaphakathi, nezenzala, yegazi kunye neenkqubo excretory.

ahlobene le ectoderm

Ectoderm - umaleko nucleation, ukusekwa iiseli equka kunye namaziko e-nervous system. lasungulwa kwenzeka ekuqaleni komdlalo gastrula okwangoku. Inkqubo luvo ekuyo ebonakala kwinqanaba eliphezulu yophuhliso. Luquka ezi ingqondo kunye umnqonqo, kwakunye imicu ngabanye ukuba bandise kubo bonke ukwakheka komzimba. Amalungu Bonse kunye neenkqubo sensor nazo livela ectoderm. Njengoko umbungu ukusuka isiziba umaleko zangaphandle iiseli, yenza isigqubuthelo. Okokuqala kwaye kwephambili inyama epithelial ulusu kunye nenkqubo yokwetyisa.

ectoderm of hydra

Xa coelenterates izilwanyana ectoderm - umaleko lomzimba eqhubeka ubomi. Cinga nje ngomzekelo isakhiwo hydra wayo amanzi. Esi silwanyana maleko-ezimbini isidumbu sakhe ukhandwa ecto- kunye endoderm. Phakathi kubo ipleyiti ashinyeneyo into intercellular. iiseli ectoderm zingafani kubume, kunye nemisebenzi. Kuba okokuqala nasekusungulweni izakhiwo ezinjalo ezizodwa kuvela nje abameli coelenterates.

Isakhiwo iqulethe iiseli ulusu-umsipha ectodermal, ezinako ukukulumkisela sincipha. Enkosi kubo, hydra lujika ngathi Acrobat, ojikelezayo izithende phezu Mpondwana sakujika. Xa baboniswa iiseli zemithambo-luvo, nto leyo nayo zicwangciswe umphandle wayo umzimba, imfuyo zixinaniswe. Oku kubonisa lomsebenzi reflex. Umaleko engaphandle nayo ilahlwa intermediate iiseli ukuba kuguqulwa naziphi ezinye iindidi. Sichaza kwinqanaba eliphezulu kwakhona amanzi hydra. Kunokuba ukubuyisela ngokupheleleyo emzimbeni wakho, nokuba bekwimo mushy.

Yintoni na le iiseli abuhlungu

Ectoderm - yinto zangaphandle leyo isebenza njengendlela ethembekileyo yokuzikhusela nokuzingela. Lo msebenzi wenziwa iiseli ehlabayo. Ziqulethe capsule kunye ngomsonto ephothiweyo ngaphakathi. Xa ixhoba idlule, iyeza ukuba uboya ezibuthathaka. Ngenxa yoko, ngalinye ngomsonto abuhlungu kwaye ngokunamandla iluma emzimbeni wakhe. Kunye kuyo kuqaliswa izinto eziyityhefu. ixhoba wakhubazeka ngokusebenzisa okuva na sayo isisu, apho ekugayeni. Uninzi iintlobo jellyfish ukuba ayingozi ebantwini. Usebenza iiseli zabo abuhlungu ebangela ukutsha kakhulu, uphazamiseko entliziyweni inkqubo yokuphefumla, kwaye maxa wambi nkqu iziphelo kunye nokufa.

Ngoko ke, lo ectoderm lo maleko yintsholongwane engaphandle, ukusuka apho inkqubo yokugaya kwi lomqolo ezimile izingxobo umzimba kunye namaziko e-nervous system. Xa coelenterates ectoderm yenza inani leeseli ezizodwa: ulusu, izihlunu, esiphakathi, luvo ahlabayo.