Feteleza amatanthauza njira yothandizira maselo a amuna ndi akazi (kugonana ndi dzira), zomwe zimabweretsa kubadwa kwa moyo watsopano. Feteleza za ovum, excreta, zizindikiro za mimba zimawerengedwa.
Umuna
Kumapeto kwa chiwerewere, nyemba yomwe ili mumsana wamphongo imadutsa mumtanda. M'chiberekero cha chiberekero, umuna umadyetsedwa mu zamchere zamchere zamkati. Kenaka akupitiliza kuyenda kwawo, kulowa mkati mwa mazira (fallopian). Mtunda umene umuna umapita ndi masentimita 20 okha, koma kulingalira kukula kwa selo lachiberekero la mwamuna, akhoza kutenga maola awiri kuti agonjetse njirayi.
Kulimbana ndi moyo
Kutsekemera kwa pafupifupi 300 million spermatozoa kumasulidwa, koma gawo laling'ono (pafupifupi zikwi khumi) limakafika ku falsipian tube komwe dzira liri. Ngakhale zochepa zimapezeka mwachindunji ndi dzira. Mbali yaikulu ya spermatozoa imawonongedwa mu chikhalidwe choopsa cha chiberekero, ndipo imabalalanso m'magulu osiyanasiyana a ziwalo zoberekera. Spermatozoons amatha kupeza manyowa, pokhapokha atakhala nthawi yina mu thupi lachikazi. Zachilengedwe zomwe zimapezeka m'magazi zimayambitsa spermatozoa, zomwe zimachititsa kuti miyendo yawo ikhale yolimba kwambiri. Kusuntha kwa umuna pamatenda amtunduwu kumathandizidwa ndi chiberekero cha chiberekero. Prostaglandins yomwe imapezeka mumadzimadzi a seminal, komanso ochotsedwera m'mimba yazimayi, imalimbikitsa izi.
Ovom
Pambuyo pochoka ku follicle panthawi ya ovulation, dzira limatulutsidwa kunja kwa chiwalo cha uterine ndi mawonekedwe onga mawonekedwe a maselo omwe akuphimba khola lamagetsi. Kusakaniza kwa dzira ndi spermatozoon kawirikawiri kumapezeka kumbali ya chiberekero cha uterine pafupi ndi maola awiri pambuyo pa kugonana. Panjira yopita ku dzira la dzira pothandizidwa ndi chinsinsi cha kachilombo ka akazi, spermatozoa imataya cholesterol, yomwe imafooketsa ma membrane awo. Ndondomekoyi imatchedwa kuti calacitation - popanda feteleza n'zosatheka. Kamodzi pafupi ndi dzira, spermatozoon ndi "kukopa" kwake. Akamalankhula ndi spermatozoa pamwamba pa oocyte, ziwalo zawo zowonongeka zimawonongedwa, ndipo zomwe zili m'magulu onse a acrosome (omwe amakhala ndi umuna wa umuna) zimasiya chilengedwe.
Kulowerera
Mazira a umuna omwe ali kutali ndi omwe amachititsa kuti dzira - cumulus masentimita ndi chipolopolo chowala. Pofuna kubzala dzenje lokwanira kuti lilowemo m'mimba imodzi, zimakhala zovuta kuti mukhale ndi nembidzi zokwana mahekitala 100. Motero, ambiri a spermatozoa omwe amafika pa oocyte "kudzipereka enieni" pofuna kulumikiza umuna wina mumsana wake. Kutsegula kwa spermatozoon mu dzira, kusanganikirana kwa mazira awo akuchitika. Zotsatira zake zimayamba kugawidwa, zomwe zimachititsa kuti mwanayo atuluke.
Kutangotha kumene umuna umalowa mu dzira, mankhwala amachititsa kuti mankhwala ena asakwaniritsidwe, kuti asapangidwe ndi zina zotchedwa spermatozoa.
Gawo lachiŵiri la meiosis
Kulowa mkati mwa dzira la spermatozoon mu dzira kumakhala chizindikiro cha kukonzanso gawo lochepa la kuchepetsa (gawo lachiwiri la meiosis) lomwe linayambira pa nthawi ya ovulation. Izi zimapanga galloid ostida ndi thupi lachiwiri la polar (limene limapanga njira zosokoneza). Kenaka nuclei ya spermatozoon ndi ovum imapanga kupanga dipyidide zygote yomwe ili ndi mabala a makolo onsewo.
Kupanga pansi
Kugonana kwa mwana wamtsogolo kumayambika kale pa siteji ya umuna. Chimene chidzakhale, chimadalira umuna basi. Chiwerewere cha mwana wamwamuna chimadalira kukhalapo kwa X kapena Y kromosome. Kuchokera kwa mayi, mwanayo amatenga khungu la X chromosome yekha, koma kuchokera kwa bambo akhoza kupeza ma chromosome a X- ndi Y. Choncho, ngati dzira limatulutsidwa ndi umuna womwe uli ndi X chromosome, fetus yaikazi imayamba (46, XX), ndi mwana wamwamuna (46, XY) pamene ankakakamizidwa ku spermatozoon kukhala ndi Y chromosome.
Kusiyanitsa kwa magulu
Maola angapo pambuyo pa umuna, magulu angapo amagawidwe amapezeka mu zygote, zomwe zimayambitsa kupanga khungu la maselo otchedwa morula. Maselo a Morula amagawanila maola 12-15 onse, chifukwa amayamba kukhala blastocyst, yomwe ili ndi maselo pafupifupi 100. Blastocyst imatulutsa mahomoni otchedwa chorionic gonadotropin, omwe amalepheretsa kuti thupi la chikasu lizikhala ndi progesterone. Pafupifupi masiku atatu mutatha kubereka, blastocyst imayamba kusunthira pang'onopang'ono kupita mu uterine. Muzochitika zachilendo, iye sakanatha kugonjetsa sphincter ya chulo lamakono. Komabe, kuchulukitsidwa kwa progesterone ndi chikasu thupi, atatha feteleza, kumalimbikitsa kusangalala kwa minofu ndi kuyenda kwa blastocyst mu uterine cavity. Kuwonongeka kapena kugwidwa kwa lumen ya uterine chubu, yomwe imalepheretsa patsogolo blastocyst pa siteji iyi, imatsogolera ku kukula kwa ectopic mimba, kumene mluza umayamba kukula mkati mwa chubu.
Mimba yambiri
Kawirikawiri, mayi amakhala ndi dzira limodzi pamwezi (kuchoka pa ovary iliyonse). Komabe, nthawi zina, mazira amasulidwa panthawi imodzi. Amatha kubereketsedwa ndi spermatozoa osiyanasiyana, zomwe zimayambitsa kukula kwa mapasa a heterozygous. Pankhaniyi, mwana aliyense ali ndi malo osiyana. Kawirikawiri dzira la feteleza limagawidwa pang'onopang'ono, m'magazi awiri omwe amapangidwa. Izi zimabweretsa chitukuko cha mapasa ofanana, omwe ali ndi magawo ofanana ndi majeremusi ndi placenta wamba. Kulekanitsa kosayenera kwa dzira maola angapo pambuyo pa umuna kumabweretsa maonekedwe a mapasa a Siamese.
Kukhazikitsa
Atagwira chiberekero cha chiberekero, blastocyst imapangidwira mu mzere wambiri wa khoma lake. Mahomoni otulutsidwa ndi blastocyst amaletsa kukanidwa ngati thupi lachilendo. Kuchokera poyambira bwino kwa blastocyst, mimba imayamba.
Matenda opititsa patsogolo
Pafupifupi gawo limodzi mwa magawo atatu aliwonse a mazira oikidwa mu dzira la feteleza samachitika, ndipo mwana wosabadwayo amamwalira. Koma ngakhale kuti mazira ambiri amapangidwa bwino, mazira ambiri amakhala ndi zilema (mwachitsanzo, kromosome yowonjezera). Kuphwanya koteroko kumabweretsa imfa ya mwana wosabadwayo atangoyambika. Nthawi zina izi zimachitika musanafike msambo, ndipo mkazi sangadziwe ngakhale pang'ono kuti mimbayo inalephera.