Ngaphambi kokubeletha
Yisiphi isibonakaliso sokuqala komsebenzi esingaziwa, kodwa kukho izinto ezininzi ezichaphazela ukuqala kweemeko ezibangelwa ukuzalwa komntwana. Inqanaba leprogesterone, elizaliswe yi-placenta egazini legazi lomama, lifikelela kwinani lephambili ngaphambi kokuba kuhanjiswe. Iprogesterone yi-hormone ejongene nokugcina ukukhulelwa. Inomphumo wokuphumla kwi-musculature evulekileyo yesisu.
Iimpawu zeHormonal
Ngokusondele ekupheleni kokukhulelwa, indawo ye-intrauterine iyancipha, kwaye ukuhanjiswa kwe-oksijini kumntwana kuhla kwehla (i-placenta ayikwazi ukuhlangabezana neemfuno zentsana ekhulayo ngokukhawuleza). Oku kukhokelela ekukhuselweni kwe-horrenone ye-adrenocorticotropic (ACTH) kwi-lobe yangaphakathi ye-fetal pituitary gland. I-ACTH igqugquzela i-correnx ye-adrenal, efihla i-glucocorticoids, eyenza umonakalo wokukhawuleza kwi-secretion ye-progesterone kwi-placenta. Ngexesha elifanayo, izinga le-estrogen eliveliswa yi-placenta liba likhulu, elihambelana nokubonakala kwimizimba yamascle ye-uterus receptors ye-oxytocin (i-uterus iba ne-sensitive to oxytocin).
Ukuqinisekisa
Kancinci, umphumo we-progesterone we-progesterone kwiimpawu ze-muscle ezihamba kakuhle zixhaswa yimpembelelo ekhuthazayo ye-estrogens. Ukhulelwe uqala ukuziva ulwaphulo oluthile olubuthakathaka olungabonakaliyo, olubizwa ngokuba yi-Braxton-Hicks contractions. Ziba negalelo ekunciphiseni komlomo wesibeleko ekulungiseleleni ukuzalwa komntwana kwaye bahlala bephosakele ngenxa yowesifazane njengesiqalo sokubeletha. Ekupheleni kokukhulelwa, i-receptors yokwandisa umlomo wesibeleko isebenzise i-hypothalamus yomama (indawo yengqondo), eyenza i-pituitary ikhuphe i-hormone oxytocin. Le hormone ivelisa ezinye iiseli zesisu. Xa izinga le-oxytocin landa, i-placenta iqala ukwenza i-prostaglandin, eyenza ithathe inxaxheba kwimivalo ye-uterine.
Ukuqiniswa kweengxaki
Njengoko ubele luba lukhuni ngakumbi kwi-oxytocin, iincwadana zikhula ngokunyuka kwaye zanda. Ukuqhekeza okuqinileyo okubonisa ukuqala komsebenzi. Njengoko iziphambano ziqinisa, indlela yokwenza ingxelo efanelekileyo inikezela ukwanda kwe-oxytocin, leyo leyo ikhokelela kwiinkcenkceshe ezininzi ze-uterine. Le ndlela iphela ukusebenza emva kokunikezelwa, xa umlomo wesibeleko unqunyulwa. Inkqubo yokubeletha iyahlula zibe zigaba ezintathu: ukuvulwa komlomo wesibeleko, ukuxothwa kwe-fetus nokuzalwa kwepentecenta.
Ukwazisa
Kuyo intloko yomntwana inokudlula kwi-canal yokuzalwa, umlomo wesibeleko kunye nesiswini kufuneka solule malunga no-10 cm ububanzi. Ukuzalwa komntwana kuqala ngokuchasana okungaqhelekanga kwinqanaba le-uterus. Ezi zincinci zokunciphisa ezidlulileyo malunga nemizuzwana engama-10 ukuya kwi-30 ukuya kweyure. Njengoko abasebenzi beqhubeka, iinqhezu ziba ziqhelo kwaye zihamba ngokuthe gqolo kwinxalenye engezantsi yesisu. Intloko ye-fetus presses malunga nombele wesibeleko kuyo yonke into eyenziwe, eququzelela ukuvula kwayo kunye nokuvula kancane. Ngexesha elithile, umlenze we-amniotic okhusela umntwana ngexesha lokukhulelwa, kunye nokuphuma kwe-amniotic fluid, ihla.
Ukufakwa
Ixesha lokubhengezwa lixesha elide kakhulu labasebenzi, elihlala kwiiyure eziyi-8 ukuya kwezi-24. Kule nqanaba, umntwana uqala uhambo lwakhe kunye nomgudu wokudala, ngokukhawuleza wenze ukujika. Ekugqibeleni, intloko ifakwa kwi-pelvis encinci yowama. Isigaba sesibini sezabasebenzi siqala ngokubhengezwa ngokugcwele komlomo wesibeleko kude kube ngumzuzwana wokuzalwa komntwana. Ngokuchazwa ngokugcwele komlomo wesibeleko, ukuphambana okunamandla kunokugqibela malunga nomzuzu kwaye uphinda rhoqo emva kwemizuzu 2-3.
Imizamo
Ngeli thuba umama ufumana isifiso esingenakunqwenelekayo sokutshiza ngeesisu zomzimba. Esi sigaba sinokugqibela ukuya kwiiyure ezimbini, ngokubeletha ngokuphindaphindiweyo ngokuqhelekileyo kuncinci.
Ukuzala
Ukulungiswa kwentloko kuqala xa umthamo wayo omkhulu ufikelela kwisini. Ngokuqhelekileyo ukunweba ngokugqithiseleyo kwesini kuhambelana nokuphuka kwayo. Emva kokuvela kwentloko, lonke umzimba womntwana uzalwe ngaphandle kobunzima. Kwintloko yesalathiso yowokuqala ngedalesi yokuzalwa idlula inxalenye enkulu ye-fetus - intloko ephakamisa umlomo wesibeleko. Kule meko, umntwana unokuqalisa ukuphefumula ngaphambi kokuba azalwe ngokupheleleyo. Isigaba sokugqibela somsebenzi - ukuzalwa kwepentecenta - ithatha malunga nemizuzu engama-30. Emva kokuzalwa komntwana, izicatshulwa zesigqirha zesisu ziqhubeka. Uxinzelelo lweemithi zamanzi ze-uterine luyekelela ukuphuma kwamanzi. Ukunciphisa iindonga ze-uterine kubangela ukuhlukana kwe-placenta. I-placenta kunye nezibilini (ezikugqibela) zisuswe kwisigxina se-uterine ngokutsalathisa ngobumnene intambo. Ukuze ugweme ukukhupha ixesha elide kunye nosulelo emva kokunikezelwa, zonke iziqwenga ze-placenta kufuneka zisuswe kwisibeletho. Ukungabikho komthi we-artery kudla ukudibanisa neengxaki ze-cardiovascular of the fetus, ngoko rhoqo hlola inani leenqanawa kwintambo yomlomo.
Amanqanaba amahomoni
Amanqanaba e-estrogens kunye ne-progesterone egazini lamanina ngokukhawuleza emva kokuzalwa komthombo wabo-i-placenta. Kwiiveki ezine ukuya kwetlanu, isibeletho sincitshiswa kakhulu, kodwa sihlala sikhulu ngokukhulu kunokuba singakhulelwa. Ngoku siyazi ukuba ziqala nini iimpawu zokuqala zabasebenzi.