Mu mazira ambiri, maselo ogonana a mayi (ovules) okhwima, mavuto omwe amaphatikizapo mavuto omwe ali ndi pakati pa mwanayo. Ndipo komabe selo ili ndi lamphamvu kwambiri pakati pa ena ambiri.
Ndi ova angati mu thupi lachikazi?
Ngakhalenso m'mimba mwa mayi, mtsikanayo amalandira ma ovules angapo, omwe amazunguliridwa ndi ma follicles. Kwa mtsikana woberedwa, chiwerengero cha mazira ndi mamiliyoni angapo, ndipo achinyamata omwe ali ndi zaka zikwi mazana angapo ali okha. Ndikofunika kukhala ndi lingaliro la momwe angaperekere mkazi, ndipo amvetse kuti ndi zaka, chiwerengero chawo sichikuwonjezeka. M'malo mwake, zimangowonjezereka. Kwenikweni, mosiyana ndi umuna wamwamuna, dzira silinayambitsenso mkaziyo. Amakhulupirira kuti ali ndi zaka 35 ali ndi mazira pafupifupi 70,000, ambiri omwe ali olakwika. Koma ngakhale mazira angapo amakhala okwanira kuti mayi atenge mimba.
Ndondomeko ya kusasitsa kwa dzira
Dzira limayamba kukhwima paunyamata, pamene kukhazikitsidwa kwa msambo. Choncho, zikuonekeratu kuti nthawi zambiri ovum amachokera nthawi ino - izi zimachitika kamodzi pamwezi. Pa nthawi ya ovulation, pamene dzira lokhwima limasiya mazira ndi kutumizidwa ku spermatozoon, mkaziyo ali ndi mwayi wokhala ndi pakati.
Nthawi ya kusasitsa kwa dzira ikhoza kukhalapo kuyambira masiku asanu ndi atatu kufikira mwezi umodzi, koma pafupipafupi imatenga masabata awiri. Choyamba, pogwiritsa ntchito mahomoni opatsa mphamvu, follicle imayamba kukula mu ovary. Amadziwika kuti ndi ovules angati mu follicle amodzi osankhidwa kuti apange mavenda pamthambo uwu. Choyamba, kukula kwake kwa dzira ndi millimeter imodzi, ndipo patadutsa milungu iwiri ikokafika pa masentimita awiri. Kutsekemera kumachitika pakati pa kayendetsedwe kake, pamene chiberekero cha pituitary chimatulutsa kuchuluka kwa homoni ya luteinizing. Nthawi ya moyo wa ovum pambuyo pa ovulation ndi maola 24.
Mzimayi amakhala ndi moyo pafupifupi ma 400 pachakudya, zomwe zikutanthauza kuti mazira masauzande m'thupi mwake ayenera kukhala okwanira kuti abereke. Koma vuto sikuti kokha ndi zaka za ova zimakhala zochepa, komanso kuti pang'onopang'ono zimataya khalidwe lawo. Choncho, nthawi zambiri nkofunika kudziwa ma oocytes angati omwe ali nawo pakali pano komanso momwe alili. Njira zatsopano zosankhira malo osungiramo mazira zimakonzedwa. Chiyeso choyesera cha chiwerengero cha mazira ndi mayeso a EFORT, omwe amachititsa yankho la ovary kuti likhale loyambitsa timadzi timene timatulutsa thupi.