| |
O Período Embrionário (As Primeiras 8 Semanas)
Desenvolvimento Embrionário: As Primeiras 4 Semanas
Capítulo 3 Fertilização
|
| |
| Nawukhuluma ngekwebhayologi,
"kwakheka kwemuntfu kucalisa
ngekwakheka kwembewu,"
ngalesikhatsi indvodza nemfati
bahlanganisa 23 ngamunye
wemakhromozomu abo
lokwenteka ngekuhlangana
kwetinhlayiya tabo tekutala.
Inhlayiya yemfati yekutala ibitwa
ngalokwetayelekile ngekutsi "licandza"
kepha ligama lakhona
lelifanele yi-usayithi.
Ngalokufanako,
inhlayiya yendvodza yekutala
yatiwa ngalokwetayelekile
ngekutsi "budvodza"
kepha ligama lelinconotekako
lakhona yispemathozoni.
Ngemuva kwekutsi sekuphume
i-usayithi esibeletfweni semfati
lokwenteka ngendlela lebitwa
ngekutsi kuphuma kwelicandza,
i-usiyothi kanye
nespemathozoni kuyahlangana
ngekhatsi etfunjini linye
lematfumbu esibeletfo,
lekuvamise kubhekiswa kuwo
njengemaFalophiyeni shubhu.
Ematfumbu esibeletfo
achumanisa sibeletfo semfati
neyutherasi kumbe sibeletfo.
I-emrbiyo lenenhlayiya yinye ledaleka
lapho ibitwa ngekutsi yizayigothi,
lokusho kutsi "lokuboshelwe
kumbe lokuhlanganiswe ndzawonye."
|
Capítulo 4 DNA, divisão celular e Fator Inicial da Gravidez (EPF)
|
| |
| Emakhromozomu la-46 ezayigothi
amelele sigaba sekucala
lesingakavami sesitfombe
semfanekiso lophelele weluhlelo
lwelufuto lwemuntfu lomusha.
Loluhlelo lolukhulu
lolu luhlala
ngekhatsi etinhlayiyaneni
letisongekile tacina
letibitwa ngekutsi yi-DNA.
Ticuketse telayeto
letimayelana nekwakheka
kwawo wonke umtimba.
Tinhlayiyana te-DNA tifana
nesitebhisi lesishwilekile
lesatiwa ngekutsi
yi-double helix.
Letenyuko talesitebhisi tentiwe
ngetinhlayiyana letihamba ngatimbili,
kumbe emabheyisi, labitwa
ngekutsi yigwanayni,
sayithosin, adenayni,
ne-thaymin.
|
| Igwanayni ihambisana ngakubili
nesayithosin kuphela,
kutsi i-adenayni
yona ihambisane nethaymin.
Leyo naleyo inhlayiya yemuntfu
Icuketse cishe 3 wetigidzi tetigidzi
talamabheyisi lahamba
ngamabili.
I-DNA yenhlayiya yinye icuketse
lwati lolunyenti kangangekutsi
kube bekulwati lolubhalwe
ngemagama,
kubhala nje kuphela luhlu lweluhlavu
lwekucala lwaleyo naleyo bheyisi
bekutawudzinga ngetulu kwemakhasi
lasigidzi netinkhulungawane
letingemakhulu lasihlanu embhalo!
Nakube beyingandlalwa
phansi ilandzelane,
i-DNA lesenhlayiyeni yemuntfu yinye
beyingalingana na-3 1/3 wemafidi
kumbe 1 mitha.
|
| Kube besingayelula
yonkhe i-DNA
lengekhatsi kwetinhlayiya
letisemntfwini lomdzala
letilikhulu lemathriliyoni,
beyingaba libanga lelingetulu
kwemamayela langemashumi lasitfupha
nakutsatfu wemabhiliyoni.
Leli libanga lelingangekusuka
emhlabeni uye elangeni uphindze ubuye
tikhatsi leti-340.
|
| Cishe 24 kuye ku-30 wema-awa
ngemuva kwekwakheka kwembewu yemuntfu,
izayigothi iyacedza kwehlukaniseka
kwekucala kwenhlayiya yayo.
Ngendlela yechubo
yemayithosis,
inhlayiya yinye ichekeka ibe
tinhlayiya timbili,timbili
tichekeke tibe tine, njalonjalo.
|
| Emuva le kusaphele 24 kuya ku 48 wema-awa
kucalise kwakheka kwembewu yemuntfu,
kungacinisekiswa kwekutsi umuntfu
utetfwele ngekutsi kutfolakale ihomoni
lebitwa ngekutsi "luphawu
lwekucalisa kutetfwala" engatini yenina.
|
Capítulo 5 Estágios Iniciais (Mórula e Blastocisto) e Células Tronco
|
| |
| Ngemuva kwa-3 kuya ku-4 wemalanga
kwakheke imbewu yemuntfu,
tinhlayiya letichekeka emkhatsini
te-embriyo tiba yindzingilita
bese kutsi i-embriyo ibitwa
ngekutsi yimorula.
Emalangeni la-4 kuya ku-5, kwakheka imbobo
ngekhatsi kwendzingilita yetinhlayiya
bese kutsi i-embriyo seyibitwa
ngekutsi yiblastosist.
Tinhlayiya letingekhatsi
kweblastosist
tibitwa ngekutsi ngumhlambi
wetinhlayiya tangekhatsi
futsi ngito letakha inhloko,
umtimba,kanye naletinye takhiwo
letibalulekile emntfwini
lowakhekako.
Tinhlayiya letingekhatsi
kwemhlambi wetinhlayiya tangekhatsi
tibitwa ngekutsi tinhlayiyasicu
te-embriyo ngobe tiyakwati
kwakha leyo naleyo yaletinhlobo
tetinhlayiya letingetulu kwa-200
leticuketfwe ngumtimba wemuntfu.
|
Capítulo 6 1 a 1½ Semanas: Implantação e Gonadotrofina Coriônica Humana (hCG)
|
| Ngemuva kwekuhamba
yehle ngelitfumbu lesibeletfo,
i-embriyo leseyincane
itinamatselisa
emtsangaleni wangekhatsi
wesibeletfo senina.
Lenchubo lena, lebitwa ngekutsi
kumila, icalisa ngemuva kwa-6 wemalanga
ibuye iphele ngemuva kwa-10 kuya ku-12
wemalanga yakhekile imbewu yemuntfu.
Tinhlayiya te-embriyo lekhulako
ticalisa kukhipha ihomoni
lebitwa ngekutsi yikhoriyonikhi
gonadothrophini yemuntfu,kumbe i-hCG,
lekuyintfo leba khona kuletinyenti
tinhlobo tekuhlola kutsi
umuntfu utetfwele yini.
I-HCG itjela emahomoni
latfolakala ebafatini
kutsi atsikamete luhlelo
wekuya esikhatsini tinyanga tonkhe
ngalokwetayelekile,
kuze kutetfwala kuchubeke.
|
Capítulo 7 A Placenta e o Cordão Umbilical
|
| Ngemuva kwekumila,
tinhlayiya letile
emaphetselweni eblastosisti
tihlumisa incenye yesakhiwo
lesibitwa ngekutsi yiplasentha,
lekungiyo leba ngumchumanisi
emkhatsini wetinhlelo temitsambo yengati
tenina nete-embriyo.
Iplasentha iletsela umuntfu
Lowakhekako i-oksijini, kudla,
emahomoni, kanye nemutsi
lokusuka kunina;
ikhiphe konkhe lokulahliwe;
futsi ivimbele kutsi ingati
yenina ingahlangani nengati
ye-embriyo nefithasi.
Iplasentha iphindze
ikhicite emahomoni
futsi igcine lizinga lekushisa
kwemtimba we-embriyo nefithasi
lisetudlwana kancane
kunelenina.
Iplasentha ichumana
nemuntfu lowakhekako
ngemitsambo
yenkhaba.
Emandla eplasenta ekuniketa
Imphilo angafaniswa nemandla
eligumbi lalabagula kakhulu
lelitfolakala etibhedlela
tesimanjealamuhla.
|
Capítulo 8 Nutrição e Proteção
|
| |
| Evikini le-1,
tinhlayiya tencumbi
yetinhlayiya letingekhatsi
takha tincwencwe timbili
letibitwa ngekutsi
yihayiphoblast
kanye ne-ephiblast.
Ihayiphoblast yenta kutsi kumile
sikhwama semtfubi welicandza,
lekungilesinye setakhiwo
lesenta kutsi
unina akwati kuniketa
i-embriyo leseyincane kudla
Tinhlayiya letiku-ephiblast
takha
inyama letsambile
lebitwa ngekutsi yi-amniyoni,
lapho i-embriyo,
ngekuhamba kwesikhatsi
kulandzele ifithasi,
kutawukhulela khona aze
umntfwana atalwe.
|
Capítulo 9 2 a 4 Semanas: Camadas Germinativas e Formação de Órgãos
|
| |
| Ngesikhatsi cishe
lesingu 2 1/2 wemaviki,
i-ephiblast ibe seyakhe
3 weticubu letikhetsekile,
kumbe tingogo tetimbewana,
letibitwa ngekutsi yi-ekthodem,
i-endodem,
kanye nemesodem.
I-ectodem yenta kutsi kumile
takhiwo letinyentana
kufake ekhatsi ingcondvo,
umgogodla,
imiva,
sikhumba,
tingalo,
kanye netinwele.
I-endodem ikhicita lucwecwe
loluvalewendlalele umgudvu
wekuphefumula
kanye nemgudvu logaya kudla,
futsi imilisa tincenye tetakhiwo
letinkhulu temtimba
letifana nesibindzi
kanye nemalulu.
Imesodem yakha inhlitiyo,
tinso,
ematsambo,
ikhathilegi,
imisipha,
tinhlayiya tengati,
kanye naletinye takhiwo.
|
| Emavikini la-3
ingcondvo iyehlukaniseka
iba tigaba leti-3 letinkhulu
letibitwa ngekutsi
yingcondvo lesembili,
ingcondvo lesemkhatsini,
kanye nengcondvo lesemuva.
Kukhula kweluhlelo lwekuphefumula
kanye neluhlelo lwekugaya kudla
nako sekucalile.
|
| Ngalesikhatsi tinhlayiya
tengati tekucala
tivela esikhwameni
semtfubi welicandza,
kwakheka imitsambno yengati
kuyo yonkhe i-embriyo,
futsi kucalisa nekubonakala
inhlitiyo lemisiphasipha.
Masinyane emvakwaloko,
inhlitiyo lekhula masinyane
iyatisonga ivaleke
ibe ngemagumbi lehlukene
icalise kwakheka.
Inhlitiyo icalisa kushaya
emavikini la-3 nelilanga linye
ngemuva kwekwakheka
kwembewu yemuntfu.
Luhlelo lwekuhamba kwengati
luhlelo lwekucala lwemtimba,
kumbe licembu letitfo temtimba
letihambisanako,
lolucalisa kusebenta.
|
Capítulo 10 3 a 4 Semanas: O Dobramento do Embrião
|
| |
| Emkhatsini wemaviki la-3 nala-4,
luhlelo lwemtimba
lucalisa kubonakala
ngalesikhatsi ingcondvo,
umgogodla,
kanye nenhlitiyo ye-embriyo
sekubonakala kalula
eceleni kwesikhwama
semtfubi welicandza.
Lokukhula masinyane
kubangela kutsi
i-embryo lekungashiyo
kutsi isicabati ivaleke.
Lenchubo lena ifaka
incenye yesikhwama
semtfubi welicandza
ngekhatsi elucwecweni
lwemgudvu logaya kudla
bese kwakheka sifuba
kanye nendzawo yesisu
kwalomuntfu lowakhekako.
|
