Ndezvipi zvikamu zve embryogenesis?
Nguva yekubamoniro yekufambira mumunhu inotora mwedzi miviri - iyi ndiyo nguva yakareba nzira dzekushandura kwema embryo kusvika mu fetus pakupedzisira. Somugumisiro wekuita uku, muviri unoumbwa unenge wakafanana nemafungiro emuitiro sezvakaitwa munhu mukuru.
Pakutanga rekutanga, zygote inoumbwa. Inoumbwa semugumisiro wekusanganiswa kwemasero evanhukadzi nevakadzi. Iyi nguva yakapera nguva pfupi. Mushure mekunge kwasvika danho rekuparadzaniswa.
Munguva iyi, yakawanda sekuwedzera kwemasero inoitika. Muchiitiko ichi, masero akaumbwa nekupwanya ainzi blastomer. Kutanga kuunganidza zvishoma masero aya kunoumbwa, iyo yakafanana nemisipiresi ye-raspberry mukati maro, uye yakanzi morula. Nekuwedzera kuparadzaniswa, nhamba yemasero inowedzera uye morula inotora chimiro chakakomba, blastula.
Mushure mekupwanya, chinotevera, chetatu chema embryonic nguva yekuvandudzwa kwechimiro, kugadzirisa. Inotora kushandurwa kwe-single-layer embryo mu-two-layered one, i.e. kungotaura chete - kune kuwirirana kweihove. Muchiitiko ichi, gastrula pachayo inoumba 2 mashizha embryonic, ecto- uye endoderms. Munguva yekushanduka kwezvinhu zvose zvipenyu, nzira yekugadzirisa muviri yakaoma nekuumbwa kweaxial complex (a neural tube, axial skeleton, musculature), iyo yakaiswa pachikamu chechikamu chema embryo kubva pamashizha matatu em embryonic.
Nguva yechina inosanganisira kuparadzana kwemashoko makuru ehengo nenyama, pamwe nekuvandudza kwavo mberi. Pamwe neizvi, pane kubatana kwakasimba kwezvikamu muhumwe chete. Saka, kubva pakatarisana nechokunze kwegadziriro, kugadzirwa kwepithelial tissue inogadzira chirwere chekudya, pamwe chete nemaronda ayo. Kubva kuMesoderm - mishonga, uye epithelium ye genitourinary system, serous membranes yeuropi. A mesenchyme inoumba chibatanidza, chechiratiginous, bone bone, vascular system.
Kuiswa kwezvikamu zvikuru uye zvirongwa zvinoitika sei?
Mushure mekunge rongororai matanho ose emakrisoni ekuvandudza, tichataurirawo masangano uye nhengo dzinoumbwa pane imwe neimwe yemavhiki avo. Nokudaro, kushandiswa kwekupwanya panguva yekuumbwa kwemwana wemukomana kunotora mazuva anenge 3-4. Munguva ino, inofamba mberi nemakumbo mairi kusvika kumugero. Somugumisiro wekugadziriswa kubva kuBlastomeres iri pamusoro pevhu, hove yakaumbwa, inobatanidzwa mukugadzirisa kudya embryo, trophoblast. Izvo blastomeres, iyo inowanikwa zvakananga pakati, inoumba embryoblast, iyo iyo yomuviri weramangwana we embryo inoumbwa.
Inenge kubva pavhiki yechipiri yekutanga kwekugadzirwa kwehutachiona, embryo inomiririrwa mumadziro emuviri. Panguva imwecheteyo, kuumbwa kwezvivako zvakadaro sejack uye amniotic vesicles zvinowanikwa. Mushure mekunge vaumba mesenchyme, amnion inoumbwa. Izvi zvinongova chidimbu chinoputika chinoumba bhegi, iyo inowanzozadzwa nezvose zvinonzi amniotic fluid.
Panenge yevhiki yechitatu yekugadzirwa kwemumikononi, bundu rakaoma remasero rinokura rinosunungurwa kubva kumashure kwembryo. Iyo inonzi inonzi musoro chikamu, kuwedzera, inoumba chinonzi nodule chikuru. Icho chimiro chinoita kuti pave nemafungiro akadaro ekugadzirisa saiyo neural tube.
Pamasvondo mana kunze kwemamwe membrane, the embryo inotangira chikamu chikuru sechikonzero chekusimudzirwa kukura, i.e. zvikamu zvakasiyana zvakasiyana zvemuviri fetal body zvinoumbwa. Kusiyana neizvi, danho rekutanga rekugadzirwa kwe organogenesis uye histogenesis rinoitika.
Nevhiki yechishanu yekuzvitakura, rudiments yemakumbo nemakumbo zvinogona kutsanangurwa zvakajeka, uye nevhiki yechitanhatu maikamu akaparadzaniswa muzvikamu zvikuru. Panenge pamagumo emavhiki manomwe pakutevedzera kweU.S. zvinokwanisika kuona rudiments yeminwe. Saka, pavhiki 8 (iyi ndiyo nguva yakareba sei emamryonic inopera), rudiments yehengo dzemu embbryo dzakapera.
Kuti tifungidzire zvikamu zvepamusoro zvekumbora kwemazuva ekufambira mberi, ngatiratidzei pasi petafura yavanoratidzwa.
