Pasati vhiki yechisere yekusununguka, embryo inokura, nhengo dzaro dzinoiswa, uye mushure mekunge nguva iyo embryo ine nhengo dzose dzinokosha, uye ipapo chete kukura kwavo kunoitika. Nguva inosvika masvondo masere inonzi embryonic, uye mushure memasvondo masere haisisiri mucheche, asi fetus, uye fetal period inotanga.
Maitiro okutanga ekusimbiswa kwemuviri wemunhu
Mavambo ekutanga ekugadzirwa kwebumbiro anogona kutevedzerwa nezuva. Pazuva rokutanga egg iri mu fallopian tube inosangana nehuta uye danho rokutanga - kubereka kunoitika. Uye zuva rakatevera danho rezygote rinotangira - seki rine 2 nuclei mumakumbo ayo ane haploid masero e-chromosomes, mushure mekunge kusanganiswa kwechimwe serosi uye imwe chromosome ye diploid inogadzirwa.
Rimwe zuva mushure meizvi, sero rinotanga kuparadzanisa - danho re morula kana kupwanya rinotanga, kutora kusvika mazuva mana. Sero rega rega rakakamurwa kusvikira rimwe bhora rakasara remasero rine ganda mukati me blastula rinoumbwa. Kubva mumasero ayo mune ramangwana rakagadzirwa ne trophoblast (ramangwana placenta) uye embryoblast (mwana anouya).
Nenguva yechinomwe blastula inopinda mudumbu, iyo inotanga kuvhara ma enzymes anodiwa pakutanga kwechikamu chinotevera - embryo implantation , iyo inosvika kusvika kwemazuva maviri.
Embryo mushure mokumiswa
Kungogadziriswa kunokonzera chikamu chinotevera chekuberekwa kwemukomana - gastrula. Rimwe chete bhora re embryoblast masero rinosvika bhora mbiri. Iko yekunze embryonic layer inonzi ectoderm uye inoita kuti iwedzere epithelium yeganda uye nhengo dzenherera. Ichi ndicho chikamu chekusiyanisa kwemashizha emakrisoni.
Kubva kune kunze kwekunze (endoderm) mune ramangwana, zvose epithelial chifukidziro chemuviri wechipfuva (mudumbu, mumukati, bronchi nemapapu), pamwe nechiropa nepascreas. Izvo zvidimbu zviviri zvinonamatira, kuumba mabhuni (amniotic - ramangwana amniotic fluid uye yolk - kutanga kudyisa embryo, uye senhengo yehemopoietic).
Kubvira panguva ino (iyo inopera pakutanga kwevhiki yechitatu yekutakura), chikamu chekupedzisira chekuvandudzwa kwema embryo - organogenesis - inotanga.
Nguva pfupi izvi zvisati zvaitika, embryo inovhara, ectoderm yayo inofukidza embryo kubva kunze,
Pashure pemavhiki mana, nhengo dzomukati dzomukomana dzinotanga kuiswa. Pamasvondo matanhatu, rudiments yemakumbo achaonekwa, kusvikira pakupera kwechitanhatu, mwoyo nemakamuri ayo zvinoumbwa, kusvikira kuumbwa kwenhengo dzomukati, mapapu, uye nhengo dzomukati dzinopera. Nevhiki 9, nhengo dzose uye maitiro akaumbwa zvakakwana, uye ipapo chete kusiyana kwavo kuchaitika.