Ukuphuhliswa kombindi womntu njani?
Ixesha elipheleleyo lokuphuhliswa kwamagama emzimbeni ngokuqhelekileyo lihlulwe ngokwezigaba ezine eziphambili. Makhe sixoxe ngomnye wabo ngokwahlukileyo.
Isigaba sokuqala sithuba esifutshane kwaye sibonakaliswe ukuhlanganiswa kweeseli zentsholongwane, okubangele ukubunjwa kwe- zygote.
Ngoko, ekupheleni kosuku lokuqala ukususela kwithuba lokuchumisa iseli yesini yesini, isigaba sesibini sophuhliso siqala - ukutyhoboza. Le nqubo iqala ngokuthe ngqo kwiibhulo ze-fallopian kwaye ihlala malunga neentsuku eziyi-3-4. Ngeli xesha, i-future embryo iya phambili ukuya kwisigxina se-uterine. Kufuneka kuqatshelwe ukuba uqhekeko lomntu luphelele kwaye luyinto engabonakaliyo, okubangele ukubunjwa kwe-blastula - isethi yezinto ezithile zesakhiwo, i-blastomeres.
Isigaba sesithathu , ukugcoba, kubonakala ngokuhlukana okuqhubekayo, ngexesha apho i-gastrula yenziwa khona. Kulo gastrulation liqukethe iinkqubo ezi-2: ukwakheka kombindi onobumba obubini, obuqukethe i-ectoderm kunye ne-endoderm; kunye nophuhliso oluqhubekayo, i-3 embrryonic leaf - mesoderm. Ukugcoba ngokwayo kubonakala ngento ebizwa ngokuba yi-invagination, apho iiseli ze-blastula ezifumaneka kwenye yezibonda zifakwe ngaphakathi. Ngenxa yoko, isakhiwo senziwe, esibizwa ngokuba yi-gastrocole.
Isigaba sesine sokuphuhliswa kwamanzi, ngokubhekiselele kwitheyibhile engezantsi, ukuhlukaniswa kwezinto ezisemgangathweni zezitho kunye nezicubu (organogenesis), kwakunye nokuphuhliswa kwazo.
Njani ukubunjwa kwezakhiwo ze-axial kumzimba womntu?
Njengoko kuyaziwa, malunga nomhla wesi-7 ukususela kumzuzwana wokuqumba, umbungu uqala ukufakwa kwisalathisi se-uterus. Oku kubangelwa ukukhululwa kwezinto ze-enzymatic. Le nkqubo yayibizwa ngokuba yi-implantation. Kuye kunye nokuqala kwesisu-ixesha lokukhulelwa. Emva koko, akusoloko emva kokuchumisa ukukhulelwa.
Emva kokufakelwa kwisalathisi sesisu, isangqa sangaphandle se-embryo siqala ukuqala kwe-hormone - chorionic gonadotropin. Ngokukhawuleza, ukugxininiswa kwakhe, ukunyuka, kukuvumela ukuba ukwazi umfazi ukuba uya kuba ngumama kungekudala.
Ngeveki yesi-2, ukuxhunyezwa kusekwa phakathi kwe-villi ye-fetus kunye neempahla zomzimba kamama. Ngenxa yoko, ukunikezelwa kwempilo encinci kuqaliswa ngokuthe ngcembe kwenziwa ngegazi kumama. Inkqubo yokwakhiwa kwezi zakhiwo ezibalulekileyo njengoko i-placenta kunye nentambo yomlomo iqala.
Kwimihla engama-21, i-embryo sele iqalile intliziyo, eqala ukuphumeza iziphambili zayo zokuqala.
Ngeveki yesi-4 yesigxina, xa uhlolisisa imbungu nge-ultrasound, kunokwenzeka ukuhlukanisa iimbono zamehlo, kunye neempembelelo zeemilenze zayo ezizayo kunye neepeni. Ukubonakala kwembungu kufana ne-auricle, ejikelezwe yincinci ye-amniotic fluid.
Ngeveki yesi-5, izakhiwo zobunqamlezo ebusweni bekrele lembungu liqala ukwakha: impumlo kunye nomlomo ophezulu kubonakala ngokucacileyo.
Ngeveki yesi-6, i-thymus gland iyakha, eyona nxalenye ebaluleke kakhulu kwisistim somzimba somzimba.
Ngeveki yesi-7, isakhiwo senhliziyo esesiswini siphucula: ukwakheka kwe-septa, imithwalo yegazi emikhulu. Imiqhekeza yebile ibonakala kwisibindi, iingqungquthela zenkqubo ye-endocrine ziphuhliswa.
Iiveki yesibhozo yexesha lokubambela ukuphuhliswa kwithebhile ibonakaliswe ekupheleni kwebhukhimakhi yeempawu zembumba. Ngeli xesha, ukukhula okunamandla kwamalungu angaphandle kubonwa, ngenxa yoko umbungu oba njengendoda encinci. Ngelo xesha, kunokwenzeka ukuhlukanisa ngokucacileyo impawu zesondo.
Yintoni ukuphuhliswa kwe-embryonic?
Uphuhliso lwe-Embryonic kunye ne-postembryonic - amaxesha ahlukeneyo ahlukeneyo ekuphuhlisweni kwanoma yimuphi umbutho. Ngaphantsi kwenkqubo yesibini, kuyisiko ukuqonda ixesha elivela ekuzalweni komntu ekufeni kwakhe.
Uphuhliso lwe-Postembryonic kubantu luquka amaxesha alandelayo:
- Umntwana (ngaphambi kokuba inkqubo yobushushu iqale).
- Ukukhula (umntu omdala, ovuthiweyo).
- Ixesha lokuguga, ekupheleni kokufa.
Ngaloo ndlela, kulula ukuqonda ukuba luhlobo luni lophuhliso olubizwa ngokuba yi-embryonic development, kwaye yiyiphi i-postembryonic.