I loko o nā pule 8 mua o ka hāpai ʻana, ulu ka pēpē i ka wā e hiki mai ana i ka wikiwiki ... ʻO ka mahele ʻana o ke kelepona, ka hoʻokumu ʻana o kona mau ʻōpū a me nā mea hoʻohui, a laila hele ka embryo i ka manawa i kapa ʻia ʻo embryogenesis. He aha nā pae mua nui o ke ola intrauterine? Wehewehewehe.

Ke kamaʻilio nei mākou e pili ana i kahi embryo mai ke ʻano o ka cell mua ma hope o ka hui ʻana ma waena o ka spermatozoon a me ka oocyte. A laila pili ka embryonic i ka ulu a me ka ulu ʻana o ke keiki i hānau ʻole ʻia mai kēia pae mua loa a hiki i ka pule 8 o ka hāpai ʻana (he 10 mau pule), ʻo ia hoʻi he 56 mau lā ma hope o ka hoʻoulu ʻana.

I wehewehe ʻia i ka lāʻau lapaʻau e nā ʻanuʻu 23 o Carnegie, hiki ke hoʻokaʻawale ʻia kēia manawa koʻikoʻi o ke ola intrauterine i 2 mau papa nui:

• ka hoʻokumu ʻana a me ka hoʻokaʻawale ʻana o ka embryo mai ka fertilization a hiki i ka pule 4 o ka hāpai ʻana,
• ka outline o ka embryonic organs, a hiki i ka 8th pule o ka hapai.

Ma hope o ka hoʻoulu ʻana, hoʻomaka ka embryogenesis me ka zygote, kahi cell i hānau ʻia mai ka hui ʻana o nā gametes kāne a me nā wahine a ke lawe nei i ka ʻike genetic o ka pēpē e hiki mai ana. I nā hola ma hope o kona hoʻokumu ʻia ʻana, hoʻomaka ka zygote e puʻunaue, ma ke ʻano o ka mitosis, i 2 mau pūnaewele o ka nui like (nā blastomeres), a laila i 4, a laila i 8 a puni ka hola 60 ma hope o ka fertilization, etc. -kapa ʻia ke kahua o ka mahele.

Ma waena o 72 mau hola ma hope o ka fertilization a me ka lā 4 o ka hāpai ʻana, hoʻomaka ka embryo kona neʻe ʻana mai ka puʻu fallopian a hiki i ka ʻōpū i ka wā e hoʻomau ana ka māhele cell. A laila i haku ʻia he 16 mau pūnaewele, ua like ka embryo me ka blackberry, no laila kona inoa morula. A laila, ulu ka morula i blastocyst, kahi pae e hoʻokaʻawale ai nā ʻāpana:

• ka ʻaoʻao pūnaewele puni honua, ka trophoblast, aia ma ke kumu o ka embryonic appendages e lilo i ka placenta.
• ʻO ka 3 a i ʻole 4 mau pūnaewele waena (a nui) o ka blastocyst e hoʻokumu i kahi pūʻulu i loko kahi e ulu ai ka embryo: ʻo ia. ke pihi embryoblast a i ʻole embryonic.

Ma waena o ka lā 4 a me 5 ma hope o ka hoʻoulu ʻana, hoʻopau ka embryo i kāna huakaʻi i loko o ka lua o ka ʻōpū. A laila, nalowale kona envelopes pale, ka zona pellucida. Kāhea ʻia hoʻohuʻuʻO kēia kaʻina hana nui e maʻalahi i ka hoʻopili ʻana o ka embryo i ka ʻōpū o ka ʻōpū, a ma hope o 7 mau lā ma hope o ka hoʻoulu ʻana, implantation.

I ka lua a me ke kolu o ka pule o ka hapai ana (4 a me 5 pule), ua ulu ka puu o na keena a hiki i ka manawa i hanaia ai ka embryo i loko o ka embryonic disc i hakuia he 2 a 3 papa (ai ole ia na papa mua). A laila ʻōlelo mākou ʻōpū. Mai kēia mau pepa e loaʻa ai nā ʻiʻo a me nā ʻāpana o ke keiki i hānau ʻole ʻia a ʻoi aku:

• o ka ectoblast, ʻO ka papa waho, e hānau ʻia kahi ʻāpana o ka ʻōnaehana nerve, ka epidermis, ka mucous membrane a i ʻole nā ​​niho.
• mai ka l'endoblaste, ka pae o loko, e hopena i nā ʻano o ka digestive a me ka ʻōnaehana hanu e like me ke ake a me ka pancreas.
• du E ʻike ʻia ka mesoblast i nā somites (ma ke kumu o nā ʻiʻo, nā ligaments, ka ʻili a i ʻole ka cartilage.), nā gonads (nā pūnaeka wahine e hiki mai ana), nā puʻupaʻa a i ʻole ka ʻōnaehana kaʻa.

Ke hele nei ka Embryogenesis i ke kahua koʻikoʻi hou i ka pule 4 o ka hāpai ʻana (6 pule). A laila, hoʻololi ʻia nā papa mua i loko o kahi ʻano cylindrical C-like, ma lalo o ka hopena o ka pelu ʻana o ka disc embryonic. ʻO kēia delimitation ʻO ka embryo, kahi hanana e hiki ai i kona circumscription e pili ana i nā mea hoʻopili a no laila e hōʻike mua i kona anatomy e hiki mai ana, e hana ʻia i 2 mau pae:

• I ka wā e kulou ana ma ka ʻaoʻao transverse, ʻO ka hope o ka embryo i ka wā e hiki mai ana, i kēia manawa i wehewehe ʻia e like me ka protrusion dorsal, ʻike ʻia, piʻi ka nui o ka lua amniotic, ʻo ka embryo a me kāna mau mea hoʻopili iā lākou iho.
• I ka wā lōʻihi lōʻihi, hui pū nā ʻāpana cranial a me ka caudal o ka embryo

Ua wehewehe maikaʻi ʻia, e lana ana i kēia manawa i loko o ka lua amniotic, hoʻomau ka ulu ʻana o ka embryo:

ʻIke ʻia nā ʻōpuʻu o nā lālā o luna, hoʻomaka ka puʻuwai e kuʻi, ʻike ʻia nā 4-12 somites mua ma kona ʻaoʻao hope.

ʻO ka pae embryonic a me ka organogenesis

Mai ka mahina ʻelua o ka hāpai ʻana, e ulu ana nā ʻōpū o ka embryo i ka wikiwiki. He organogenesis.

• Ma lalo o ka hopena o ka ulu wikiwiki ʻana o ka ʻōnaehana nerve, ulu a flexes ka pole cephalic o ka embryo (kona poʻo). I loko, māhele ka forebrain (forebrain) i ʻelua ma kahi o ka pule 5 o ka hāpai ʻana. ʻO kekahi hiʻohiʻona ʻē aʻe i kēia pae: ka outline o nā ʻano manaʻo.
• Ma kahi o ka pule 6, aia ia ma ka hoʻomaka ʻana o ke awāwa auditory waho e ʻike ʻia, e like me ka vertebrae, i hoʻonoho ʻia i kēia manawa a puni ke kuamoʻo, a me nā ʻiʻo hope. ʻO nā hiʻohiʻona ʻē aʻe o ka embryo i kēia pae: ʻo kona ʻōpū ke ʻano hope loa a aia nā pūnaewele moe mua.
• I ka 7 pule hāpai, hoʻomau ka ulu ʻana o nā lālā a ʻike ʻia nā ʻāwī waena ma nā lima a me nā manamana wāwae i ka wā e ʻokoʻa ai ka musculature o ka puʻuwai.

I ka pau ʻana o ka pule 8, kokoke pau ka organogenesis. Hoʻokaʻawale ʻia nā ʻāpana a e "ulu" wale nō i ka wā o ka fetal. ʻO ka ʻōpuʻu, ma kona ʻaoʻao, ua ulu aʻe kona ʻano kanaka: kū ke poʻo i luna, ua hana ʻia kona ʻāʻī e like me kona helehelena a ʻoi aku ka nui o kona mau lehelehe, ka ihu, nā maka a me nā pepeiao.

I nā pule he 9 o ka hāpai ʻana (he 11 pule), lilo ka embryo i fetus. ʻO ka manawa fetal, e mau ana mai ka mahina 3 o ka hānau ʻana a hiki i ka hānau ʻana, ʻike ʻia ma luna o nā mea āpau e ka ulu ʻana o nā ʻiʻo a me nā ʻōpū. ʻO ia hoʻi i loko o kēia māhele e ʻike ai ka fetus i ka piʻi nui o ka nui a me ke kaumaha. ʻO kahi hiʻohiʻona e haʻi nui ana: mai 3 knm a me 11 g i ka hopena o ka wā embryonic, hele ka pēpē e hiki mai ana i 12 knm a me 65 g i ka hopena o ke 3 mahina o ka hāpai ʻana!