Fertilization inoreva kushandiswa kwekusanganiswa kwemasero evanhukadzi nevakadzikadzi (sperm uye mazai), zvinotungamirira mukuzvarwa kwehupenyu hutsva. Fertilization ye oum, excreta, zviratidzo zvekudzivirira zvinowanikwa.
Mbeu
Pakupera kwechiito chepabonde, chirume chinenge chiri mumademini chemumvura chinopfuurira kuburikidza neuterine cavity. Muchibereko chechibereko, chirume chinodyiwa mumusana wealkaline wekervical mucus. Ipapo vanoenderera mberi nekufamba kwavo, vachipinda mu fallopian tubes (fallopian). Nharaunda iyo mbeu inopfuura inenge masendimita makumi maviri chete, asi ichifunga nezvehukuru hwehutachiona hunobereka sero, inogona kutora kusvika maawa maviri kuti ikurire nzira iyi.
Kurwisana kwekurarama
Ne ejaculation chiyero chema 300 mamiriyoni spermatozoa anosunungurwa, asi chikamu chiduku (anenge anenge gumi nezviuru) chinosvika kune fallopian tube apo mazai. Kunyange zvishoma zvinowanikwa zvakananga neii. Chikamu chinokosha che spermatozoa chinoparadzwa mumamiriro ezvinhu ane utsinye anowanzoita zvechikadzi, uye anopararira munzvimbo dzakasiyana-siyana dzehutachiona. Spermatozoons dzinova nekwanisi yekudiridza, kunze kwokunge apedza nguva yakati muviri wechikadzi. Zviratidzo zvehupenyu zvemuviri webonde zvinomutsa spermatozoa, zvichiita kuti kusvibiswa kwemiswe yavo kusimbe zvikuru. Kufambisa kwehutano kumusoro kwechirwere chepabonde kunoshandiswa nekugadziriswa kwechibvumirano chechibereko. Prostaglandins inowanikwa mumasikirini emumvura, uyewo akanyanyisa mukadzi kana musikana, inokurudzira izvi zvinopesana.
Ovum
Mushure mekubuda kubva muhutori panguva yekuvhenekera, mazai anodzingwa kunze kwechirevo chemukati weuyo uterine nemafungu-akafanana semafungiro akabatanidza taupipian tube. Kusangana kweii ne spermatozoon kazhinji kunowanikwa kune imwe nzvimbo yekunze uterine tube anenge maawa maviri mushure mekuita zvepabonde. Panzira inoenda kuneiyo masero pasi pemubatiro wechakavanzika chechikadzi chepabonde, spermatozoa inorasikirwa necholesterol, iyo inowedzera simba ravo rechirusi. Iyi nzira inonzi "calacitation" - kunze kwayo kubereka hazvibviri. Kamwe kamwe pedyo neii, spermatozoon "makwezva". Paunobata spermatozoa nechokumusoro kweoocyte, maitiro avo echrosomal akaparadzwa zvachose, uye zviri mukati meumwe acrosome (enzyme-ine sperm cell) inobva mumhepo.
Penetration
Isolated manyoka enzymes anoparadza maitiro edziviriro eai-cumulus mashizha uye ganda rakajeka. Kuumba gomba rakakwanira kupindira imwe spermatozoon, kuvhara kwemberi kweanenge maekare zana kunokosha. Nokudaro, vazhinji vanonzi spermatozoa vanosvika maoocyte "vanozvipira pachavo" nekuda kwekuunza imwe mbeu mukati me cytoplasm yayo. Mushure mokunge utanga wepermatozoon muzai, kuwedzerwa kwezvinyorwa zvadzo zvinowanikwa. Zygote iyo inoguma inotanga kugovana, ichipa kumera.
Pakarepo mushure mokupinda kwemuviri mukati mazai, kemikari inokonzerwa inokonzerwa, zvichiita kuti isakanganiswa kune dzimwe spermatozoa.
Chikamu chechipiri che meiosis
Kupindira kwemukati we spermatozoon muzhi inova chiratidzo chekupedzwa kwechipiri chekuparadzanisa (chikamu chechipiri che meiosis) chakatanga panguva yehuvhu. Izvi zvinoumba galloid ostida uye yechipiri body polar (iyo inotanga kuenderera mberi inogadzirisa zvirongwa). Ipapo nuclei ye spermatozoon uye ovum inobatanidza kuumba diploid zygote ine mazita ekuberekwa kwevabereki vose.
Kuumba pasi
Kuita zvepabonde kwemwana weramangwana kunoumbwa kare panhandare yekumera. Zvichazove, zvinongotarirwa chete nemurume. Izvo zvepabonde zve fetus zvinoenderana nekuvapo kwe X kana Y chromosome. Kubva kuna amai, fetus inogamuchira chete X chromosome, asi kubva kuna baba inogona kuwana zvose zve-X-uye Y-chromosome. Saka, kana mazai anogadzirwa nemurume ane X chromosome, inomusikana wechikadzi inowedzera (46, XX), uye mukomana wechidiki (46, XY) paanosungirirwa kune spermatozoon ine Y chromosome.
Cell division
Maawa mashomanana mushure mekuita, huwandu hwemitotic kuwirirana hunoitika mu zygote, zvichiita kuti kuumbwa kwebumbiro remasero anonzi morula. Masero emuMorula anoparadzanisa maawa gumi nemaviri kubva kune gumi nemashanu, zvichiguma nemhepo iyo inoshanduka kuva blastocyst, inenge inenge masero zana. Blastocyst inobereka hormone inonzi chorionic gonadotropin, iyo inodzivisa kuzvidzora kwemuviri wemiviri kubudisa progesterone. Inenge mazuva matatu mushure mekudyarwa, blastocyst inotanga kufamba nemugwagwa we fallopian kusvika muuterine cavity. Mumamiriro ezvinhu akadai, aisagona kukunda sphincter ye fallopian tube. Zvisinei, kuwedzera kwekugadzirwa kweprogesterone nejecha muviri, wakacherechedza mushure mekusimudza, kunokurudzira kuzvidzora kwemasumbu uye kufamba kweblastocyst muuterine cavity. Kukuvadza kana kuwirirana kwechiedza cheuterine tube, iyo inodzivisa kufambira mberi kweblastocyst panguva ino, inotungamirira kukurudzirwa kwe ectopic pregnancy, iyo iyo embryo inotanga kukura mukati mehutu.
Kubata pamuviri
Muzviitiko zvakawanda, mukadzi ane jira rimwechete mwedzi wega wega (zvichibva pane imwe neimwe yegavha). Zvisinei, pane dzimwe nguva, mazai anonyoreswa panguva imwechete kubva kumavhizha maviri. Vanogona kuve nekugadzirwa nemhando dzakasiyana-siyana dzepermatozoa, iyo inotungamirira kukurudzirwa kweheterozygous twins. Muchiitiko ichi, buri fetus ine nzvimbo yakasiyana yeparcenta. Kakawanda kazhinji mazai anogadzirwa anowanzoparadzanisa kuva maviri, kubva mairi maviri akasiyana-siyana akaumbwa. Izvi zvinotungamirira kukurudzirwa kwemafa akafanana, ane rimwechete rejene uye imwe nzvimbo placenta. Kuparadzanisa kwakakwana kweii maawa mashomanana mushure mekuberekwa kunotungamirira pakuonekwa kwemaJaamese mapatya.
Implantation
Sezvo zvasvika pamucheto wechibereko, blastocyst inogadzirirwa mukati mehuni mucous membrane yemadziro ayo. Mahomoni akabudiswa ne blastocyst anodzivisa kurambwa kwaro semuviri wekunze. Kubvira pakubudirira kwekuiswa kweblastocyst, pamuviri unotanga.
Matambudziko okukura
Inenge chikamu chimwe chete muzvitatu chematambudziko ekugadzika kwezai rinogadzirwa hazviitiki, uye embryo inofa. Asi kunyange nekubudirira kugadziriswa, mazai akawanda ane maitiro ekuberekwa (somuenzaniso, imwe chromosome). Kurwiswa kwakadaro kunowanzoisa kurufu rwemucheche nguva pfupi mushure mokunge yaiswa. Dzimwe nguva izvi zvinotanga kusati kwatanga kunonoka pakuenda kumwedzi, uye mukadzi angasaziva kunyange nezvekudzivirira kwakakundikana.