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O Período Embrionário (As Primeiras 8 Semanas)
Desenvolvimento Embrionário: As Primeiras 4 Semanas
Capítulo 3 Fertilização
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| Ngokwebhayiloji,
"ukukhula komuntu kuthoma ngesikhathi
sokumumatha''(fertilization)
ngesikhathi umama nobaba
bahlanganisa ama-chromosomes
wabo angu 23 ngamunye
ngokuhlanganisa amaseli wabo
wokubeletha.
Iseli lokubeletha likamama livamise
ukubizwa ngokuthi ``liqanda''(egg)
kodwa igama ekungilo yi-oocyte.
Iseli lendoda lokubeletha
laziwa ngama "sperm"
kodwa igama elikhethekileko
yi-spermatozoon.
Ukulandela ukuphuma kwe-oocyte
kuqanda lomuntu wesifazane
kukambiso ebizwa nge-ovulation,
i-oocyte ne-spermatozoon
ziyahlangana
ngaphakathi kwethumbu lesizalo,
avamise ukubizwa ngama
Fallopian tubes.
Amathumbu wesizalo ahlanganisa
amaqanda womuntu wesifazane
nesibeletho.
Isiphumelo salokho liseli
elibizwa nge-zygote,
okutjho "okuhlangeneko."
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Capítulo 4 DNA, divisão celular e Fator Inicial da Gravidez (EPF)
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| Ama-chromosomes angu 46 we-zygote's
ajamele umphumela
wokuthoma ohlukileko
wokwakheka okupheleleko
komuntu oyedwa.
Ukuhleleka lokho kuhlala
ngeencenyana ezincane ezihlangeneko
zamamolekyula ezibizwa nge-DNA.
Zinemilayezo yokukhula
komzimba woke.
Amamolekyuli we-DNA afana
Nesikhwelo esihlangeneko
esibizwa nge-double helix.
Amafindo wesikhwelo enziwe
mamolekyuli amabili,
noma ukwakheka okubizwa nge-guanine,
cytosine, adenine, ne thymine.
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| I-Guanine ihlangana kwaphela
ne-cytosine,
begodu i-adenine yona
ihlangane ne-thymine.
Iseli elinye nelinye
Lomuntu pheze libe neengidigidi ezi-3
zemakhiwo engamibili le.
I-DNA yeseli ngalinye inemininingwane
eminengi kangangokuthi
nakube beyijanyiselwe ngamagama
abhaliweko,
ngokubhala igama
ngalinye lesakhiwo ngasinye
kungadinga amaphepha abhaliweko
angaphezulu kwesigidigidi esi 1.5!
Nakube ama-DNA ahlanganisiwe,
aba liseli linye lomuntu elingange
3 1/3 yeenyawo
noma imitha eli-1.
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| Nakube besingathathulula i-DNA
ngaphakathi kwamaseli womuntu omdala
amabhiliyoni amantathu ali-100,
ingathabuluka ibe ngaphezulu
kwamamayela amabhiliyoni ama-63.
Ubude lobu bungangokusuka
emhlabeni ukuya elangeni ukubuya
kuze kube ziinkhathi ezi-340.
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| Isikhathi esinganga ma-24 ukuya kuma-30
wamahora ngaphambili kokumumatha (fertilization),
i-zygote yakha beyiqede
ukuhlukana kweseli lokuthoma.
Ngenkambiso ye-mitosis,
iseli ngalinye lihlukana kabili,
nalikabili lihlukane kane, njalo njalo.
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| Kusese mahora ama 24 ukuya kwama 48
ngemva kokuthoma ukumumatha (fertilization),
ukukhulelwa kungafakazelwa
ngokuzwa i-homoni
elibizwa "ngebanga lokukhulelwa lokuthoma"
ngaphakathi kweengazi zikamama.
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Capítulo 5 Estágios Iniciais (Mórula e Blastocisto) e Células Tronco
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| Emva kwamalanga ama 3 ukuya kwama
4 ngemva kokumumatha,
amaseli ahlukanako we-embryo
aba yindilinga
begodu i-embryo ibizwa
ngokuthi yi-morula.
Ukusukela emalangeni ama 4 ukuya kwa 5,
Kuba nesikhala hlangana nebholo yamaseli
begodu i-embryo leyo
ibizwa nge-blastocyst.
Amaseli angaphakathi kwe-blastocyst
abizwa ngobunengi bamaseli
wangaphakathi
begodu akha ihloko, umzimba,
nokunye ukwakheka
okubalulekile kumuntu okhulako.
Amaseli angaphakathi kobunengi
bamaseli wangaphakathi,
abizwa ngama embryonic stem cells
ngob akwazi
ukwenza elinye nelinye lehlobo
yamaseli angaphezulu kwa 200,
asemzimbeni womuntu.
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Capítulo 6 1 a 1½ Semanas: Implantação e Gonadotrofina Coriônica Humana (hCG)
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| Ngemva kokuya phasi nethumbu
lesizalo(uterine tube),
i-embryo yokuthoma ihlala
ngaphakathi komthangala
wesizalo sikamama.
Ikambiso le,ebizwa ngokutshaleka
yenzeka ngemva kwamalanga asi 6
iphele emva kwamalanga ali 10 ukuya ku 12
ngemva kokumumatha(fertilization).
Amaseli we-embryo ekhulako athoma
ukuba namahomoni
ebizwa nge human chorionic
gonadotropin, noma hCG,
okuyinto eveza kuhlolelwa
ukukhulelwa.
HCG ithumela amahomoni wesifazane
ukuthi athikameze ukuya enyangeni
okujayelekile (normal menstrual cycle),
avumele ukukhulelwa kuye phambili.
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Capítulo 7 A Placenta e o Cordão Umbilical
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| Ngemva kokutshaleka (implantation),
amaseli elipheleleni kwe blastocyst
akha incenye yomakhiwo
ebizwa nge placenta,
ohlukanisa okukamama
nekwe-embryo.
Iplasenta ilihlangothi
likamama eliletha umoya, okondlako,
amahomoni, nemithi kumuntu okhulako;
asusa koke okungafunekiko;
befuthi avikele igazi likamama
lingahlangani
nele-embryo ne-fetus.
Iplasenta nayo yenza amahomoni
befuthi ibambha ukushisa komzimbha
we-embryonic ne-fetus
ube ngaphezudlwana kokushisa
komzimbha kamama.
Iplasenta ikhulumisana
nomuntu osakhulako
ngemithambo yenkaba
umbilical cord).
Ubukghoni beplasenta bokusekela
ubuphilo budlula
beendawo zeembhedlela zokunakekela abagula
khulu ezitholakala eembhedlela zanamhlanjesi.
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Capítulo 8 Nutrição e Proteção
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| Evekeni yoku 1,
amaseli wamaseli
wobudisi wangaphakathi
enza amalayini amabili
abizwa nge-hypoblast
ne-epiblast.
I-hypoblast yenza 147
umgodlana womthubi,
okungomunye wemakhiwo
umama athumela ngawo
izakhiwo zomzimbha
ku-embryo nayisathomako.
Amaseli aphuma ku-epiblast akha
ithambo elibizwa nge-amnion,
ngaphakathi kwalo la i-embryo
ngemva kwesikhathi i-fetus
ikhula bekufike
isikhathi sokubeletha.
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Capítulo 9 2 a 4 Semanas: Camadas Germinativas e Formação de Órgãos
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| Ngeemveke ezi 2 no 1/2,
i-epiblast yenzekile
iinyamana ezi-3 ezikhethekileko,
noma imikhakha,
ebizwa nge-ectoderm,
endoderm,
ne mesoderm.
I-Ectoderm yona ibumbha
imakhiwo embalwa
okufaka hlangana ingqondo,
ithambo lomgogodla,
imizwa,
isikhumba,
amazipho,
neenhluthu.
I-Endoderm iveza
isikhumba sokuphefumula
neziko lokugaya ukudla,
begodu yakha iincenye zamalunga
njengesibindi
namanyaka (pancreas).
I-Mesoderm yakha ihliziyo,
iziso,
amathambo,
namathambo amade (cartilage),
imisipha,
amaseli weengazi,
neminye imakhiwo.
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| Emvekeni ezi 3
ingqondo iyahlukana
ngeencenye ezi 3 ezisisekelo
ezibizwa ngengqondo
yangaphambili (forebrain),
ephakathi (midbrain),
neyangemuva (hindbrain).
Ukukhula kwehlelo lokuphefumula
nelokugaya ukudla
nakho kusendleleni.
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| Njengoba amaseli weengazi athoma
ukuvela ngaphakathi
komgodlana womthubi,
imithambo yeengazi
yakheka ku-embryo yoke,
begodu nehliziyo elitjhubhu
ithoma ukuvela.
Kungasi kudala,
ihliziyo ekhula njalo
iyabhincana ngokwayo
njengendlwana eyodwa
ithome ukuvela.
Ihliziyo ithoma ukuphefumula
Emva kweemveke ezi-3 nelanga elilodwa
ngemva kokumumatha (fertilization).
Ihlelo lokukhambisa iingazi
lihlelo lokuthoma lomzimbha,
noma isichema samalunga ahlobeneko,
ukufikela isikhathi sokusebenza.
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Capítulo 10 3 a 4 Semanas: O Dobramento do Embrião
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| Phakathi kweemveke ezi 3 ne 4,
ihlelo lomzimbha liyathoma
njengoba ingqondo,
ithambo lomgogodla,
nehliziyo ye-embryo
zibonakala lula
eceleni komgodla womthubi(yolk sac).
Ukukhula okuya phambili
kubangela ukugoqana
kwe-embryo ethabaleleko.
Ihlelweli lifaka hlangana
incenye yomgodla womthubi
endleleni
yehlelo lokuphefumula,
yakhe isifuba
nesikhala samathumbu
womuntu okhulako.
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