Ngokukhawuleza emva kokuchumisa, inkqubo enzulu iqala - ukutyunjwa kweqanda. Iiseli ezimbini zijika zibe ezine, ngoko ziba zibhozo, emva kweeveki ezimbalwa ziba ngumbungu. Liye labeka iziko eziphambili, kwaye kwiinyanga ezili-9 iya kuba yintsana esanda kuzalwa.
Iqanda lizalisa ixesha elingakanani?
Inkqubo yokuchumisa iqanda iphela iiyure ezimbalwa nje. I-spermatozoon idlula kwi-epithelium, ejikeleza iqanda, ingene kwigobolondo yayo ibe ifinyelele kwinucleus. Kwinkqubo yokuchumisa, i-sperm isebenzisa i-enzymes ekhethekileyo ekhoyo ekupheleni kwentloko, eyinceda ukunqoba umqobo wokukhusela. Emva koko, i-ovum ayisekho enye i-spermatozoa, ukwahlula kweeseli kuqala.
Ulwahlulo lwe-Oocyte
Njengomphumo we-fusion ye-ovum kunye nesidoda esivela kwiqanda elikhulelweyo, i-zygote iyaqhubeka, isigaba sokuqala sokuphuhliswa kwembungu. Kwiiyure ezingama-24 ezalandelayo, kuya kuba yinto engekho i-unicellular eyoqala ngokukhawuleza ibe yinkqubo eyinkimbinkimbi. Kwi-zygote, inkqubo yokwenza i-nuclei (yindoda kunye nowesifazane) iyasebenza. Nganye yale nuclei inesiseko sayo se-chromosomes - indoda kunye nesetyhini. Iinuclei zenziwe kwiiphelo ezahlukeneyo ze-zygote, zithandwa omnye komnye, iigobols zichithwa kwaye zityhulwa.
Iintombi zeentombi ezakhiwe ngenxa yesahlulo zibe zincinci, zikhona kwigobolondo enye, kwaye zingabambisani. Eli xesha lihlala lifike kwiintsuku ezintathu. Emva komnye umhla, iiseli zenza i-blastocyst, equkethe iiseli ezingama-30. Leli nqanaba lokuqala lokuphuhliswa kweqanda le-fetal, ibhola elingenalutho kunye ne-embryoblast ehlanganiswe kwenye yeendonga-umntwana ozayo. I-Blastocyst ikulungele ngokupheleleyo ukufakelwa kwi-epithelium yesibeleko.
Iimpawu zoqhumiso lwe-oocyte
Ukufakelwa kwemfuyo kwenzeka kumgangatho wamaselula, ngoko ke akubonakali kumfazi. Yingakho kunzima ukuhlukanisa iimpawu eziqhelekileyo zokuchumisa iqanda. Iimpawu zokuqala zokukhulelwa zingabonwa kuphela emva kokuba iqanda elichumisiweyo lifakwe kwisibilini se-uterine, kwaye oku kuya kwenzeka, ngokuqhelekileyo, iintsuku ezi-7 emva kokuxubha kwesidoda kunye neqanda. Lo mzuzwana ungabonakalisa nje ngegazi elincinci, elithatyathwa ngumfazi ukuqala kokuya esikhathini. Ukongeza, ngokukhawuleza emva kokufaka iqanda emzimbeni, imvelaphi ye-hormone iqala ukutshintsha, kwaye impawu zokuqala zokukhulelwa ziqala ukuvela. Ngokuqhelekileyo oku kwenzekayo kungekudala kwiiveki ezi-1.5-2 emva kokuchumisa.
Kutheni kungekho iqanda elityalwa?
Kwezinye iimeko, nangona i-ovum kunye nesidoda idibana, kukho ukuphulwa kombono. Ngokomzekelo, kungenzeka ukuba i-oocyte engasetshenziswanga ifunyenwe ngokukhawuleza kunye ne-spermatozoa emibini, okubangelwa ukubunjwa
Kwimeko nayiphi na into, ukuphendula ngokuchanekileyo umbuzo othi kungani ukukhulelwa kungabikho nakwiziphi na isibini esithile, ugqirha kuphela onokukwazi ukuvavanya emva kokuvavanywa ngokucokisekileyo, kuba izinto ezininzi ezichaphazela idimbini kunye neqanda kufuneka zenze ukuba ugcino luze luhlangane.