Zochitika za pathupi, mimba ndi chitukuko chake nthawi zonse pamwamba pamwamba pa Mitu ya akazi. Ndipo, chodabwitsa, komabe, chidziwitso chokhudza maziko a "kubadwa kwa moyo watsopano" kawirikawiri chimangokhala pa "biology ndi pestle" maphunziro omwe amaphunzira m'zaka za sukulu. Tiyeni tiyese kukonzekera ndikuphunziranso momwe wina wa anthu otchulidwa m'nkhaniyi akuchitira - dzira lachikazi.
Pa kubadwa kwa mtsikana yemwe ali ndi chiberekero chake, matenda otchedwa endocrine omwe amachititsa kuti thupi lake likhale ndi mahomoni, pali ma gametes okwana 7 miliyoni - mazira (gametes), omwe aliwonse amatha kukhala maziko a moyo watsopano pambuyo pa umuna. Koma pang'onopang'ono ndi msinkhu, chiwerengero cha mazira chimakhala chochepa: zaka 20 zatha kale zikwi 600, ndipo pambuyo pa 60 sizipezeka konse. Maselo amphamvu oterewa amalola mkazi kukhala mayi ngakhale ngati imodzi kapena mbali ina ya ovary imachotsedwa.
Kotero, dzira la dzira (dzira, chiwalo) ndilo selo lalikulu kwambiri la thupi laumunthu, selo lachiberekero la kubala ndilololedwa (lomwe limapangidwira pang'ono kapena lozungulira) limene limabuka ndipo "limasungidwa" muzomwe zimayambira. Zimakhala zosavomerezeka ndipo musanafike pachiberekero zimapanga njira ya masentimita 10 m'litali kumbali ya villi ya oviduct mkati mwa masiku 4-7. Kukula kwa dzira kumakhala koposa kawiri kuposa kukula kwa umuna wa umuna - kachilombo kakang'ono kamodzi kambirimbiri - kukula kwa maselo ena m'thupi. Mimba mwake ndi ya dongosolo la 100-170 μm. Gamete yazimayi imapangidwira kupatsirana mu njira yopangira kachilogi ya haploid ya ma chromosomes 23 (22 kudziwitsira kwa chilolezo chogonana ndi munthu mmodzi X X chromosome yomwe imayenera kugonana kwa mwana wosabadwa).
Kodi dzira limawoneka bwanji?
Ndondomeko ya mazira okhwima, omwe amapangidwa pambuyo pa ovulation - kumasulidwa kwa dzira kuchokera ku follicle mpaka m'mimba, kumaperekedwa pansipa.
Kawirikawiri, dzira lili ndi mawonekedwe ofanana ndi maselo ena a thupi: phokoso, cytoplasm, kulekanitsidwa kwa membrane ya plasma. Mphuno yopanda phokoso yomwe ili ndi ma chromosome pamwambapa mu dzira ili pakati pake. Pulogalamuyi imakhala ndi ribosomes zosiyanasiyana, zomwe zimapangidwa ndi endoplasmic reticulum ndipo zimakhala ndi michere yofunika kuti ipumidwe maselo a mitochondrial. Mbali ya kunja ya cytoplasm ili ndi granules, yomwe imalowa mu dzira la umuna, yomwe imagwiritsa ntchito chipolopolo chake, zomwe zimayambitsa kusintha kwa ma oocyte ndikulepheretsanso kulowa kwa spermatozoa. Mbewu za cortical zothandizira zidzalimbikitsanso bwino feteleza.
Zigobowo za dzira zimathandizanso kuteteza zakudya zake. Kunja, dzira lozunguliridwa ndi chipolopolo chowala, chophimba ndi michira ya microvilli - iyi ndi yotchedwa follicular coat kapena crown crown.
Thupi la pola ndi selo yaing'ono yomwe, pamodzi ndi dzira, imapangidwa chifukwa cha meiosis - kugawidwa kwa selo yoyamba panthawi yosasitsa. Zakhala zatsimikiziridwa ndi sayansi kuti zomwe zili mu thupi la polar zikhoza kukhala maziko a matenda a majeremusi.
Chakudya cha selo musanayambe kulowa mu khoma la uterine kumathandizidwa ndi yolk granules-vesicles, odzaza mafuta, pang'ono mapuloteni, mavitamini ndi microelements.
Mphamvu ya selo lokulitsa dzira, limatha kusintha chifukwa cha zinthu zakuthambo monga chilengedwe, mawonekedwe a zamoyo komanso kutentha kwa dzira. Kuonjezera apo, mawonekedwe a maselo opangira mavitamini amakhala ndi zotsatira zowonongeka. "Wofooka", osati dzira la kucha nthawi zambiri limayambitsa kusabereka. Izi zikhoza kuchitika, mwachitsanzo, ngati msambo umatha masiku osachepera 21, kapena masiku opitirira 35. Muzochitika zotere, dzira la mazira lirilonse silinayambe "kucha", kapena likukhala lopanda kale. Ngati palibe ovulation, thumba losunga mazira silimapanga mapuloteni, omwe amachititsa ovulumu kukhala okhwima. Choncho, popanda mazira, pamene spermatozoa imalowa, feteleza sizimachitika.