Mumasvondo masere ekutanga enhumbu, mucheche wemangwana anoshanduka nekukurumidza … Masero ekupatsanurwa, kuumbwa kwenhengo dzayo nemaapendiges ayo, "embryo" inobva yapinda munguva inonzi embryogenesis. Ndeapi matanho makuru ekutanga ehupenyu hwe intrauterine? Decryption.

Tinotaura nezve "embryo" kubva pakuonekwa kwesero rekutanga zvichitevera kusangana kwespermatozoon neoocyte. Embryonic phase inobva yaenderana nekukura nekukura kwemwana asati azvarwa kubva padanho rekutanga chairo kusvika pasvondo resere remimba (masvondo gumi), kureva mazuva makumi mashanu nematanhatu muchangosangana.

Inotsanangurwa mukurapa nematanho makumi maviri nematatu eCarnegie, iyi nguva yakakosha yehupenyu hwe intrauterine inogona kukamurwa zvakanyanya muzvikamu zviviri zvikuru:

• kuumbwa uye kuganhurwa kwe embryo kubva pakusangana kusvika pavhiki yechina yekuzvitakura,
• rondedzero ye embryonic nhengo, kusvika vhiki ye8 yekuzvitakura.

Mushure mekusangana, embryogenesis inotanga nezygote, sero rimwe chete rinozvarwa kubva mukusanganiswa kwegeteti yechirume neyechikadzi uye yatotakura ruzivo rwemucheche remangwana. Mumaawa anotevera kuumbwa kwayo, zygote inotanga kupatsanurwa, nechiitiko che mitosis, kuita 2 masero ehukuru hwakaenzana (the blastomeres), yozoita 4, yozoita 8 paawa yemakumi matanhatu mushure mekusangana, zvichingodaro. -inonzi danho re segmentation.

Pakati pemaawa makumi manomwe nemaviri mushure mekusangana uye pazuva rechina remimba, "embryo" inotanga kutama kwake kubva pa fallopian chubhu kusvika kuchibereko apo kupatsanurwa kwesero kuchienderera mberi. Zvino inoumbwa nemasero gumi nematanhatu, embryo inofanana neblackberry, nekudaro zita rayo morula. Iyo morula inobva yashanduka kuita blastocyst, nhanho iyo maseru anosiyanisa:

• iyo peripheral cell layer, trophoblast, iri panotangira embryonic appendages inozozoita placenta,
• masero matatu kana mana epakati (uye akakura) eblastocyst anoumba masero emukati umo "embryo" inobva yabva: bhatani re embryoblast kana embryonic.

Pakati pezuva rechina ne4 mushure mekusangana, embryo inopedza rwendo rwayo muchibereko chechibereko. Inobva yarasa envelope yayo yekudzivirira, iyo zona pellucida. Zvakare kunzi hatching, danho rinokosha iri rinoita kuti kusungirirwa kwe embryo kune uterine lining, uye pakupedzisira mazuva manomwe mushure mekusangana, kuiswa.

Muvhiki rechipiri nerechitatu renhumbu (masvondo mana neshanu), boka remasero iro kusvika panguva iyoyo rakaumba embryo rinoshanduka rikava embryonic disc rinoumbwa 4 uye 5 layers (kana primitive layers). Tinobva tataura nezvazvo gastrulation. Kubva pamapepa aya zvinozoguma matishu uye nhengo dzemwana asati azvarwa uye kunyanya:

• ye ectoblast, kunze layer, ichazvarwa chikamu chetsinga, epidermis, mucous membranes kana mazino.
• kubva kul'endoblaste, yemukati layer, inozokonzeresa nhengo dzekugaya nekufema system pamwe nechiropa uye pancreas kunyanya.
• du mesoblast inozoonekwa somites (kunobva tsandanyama, ligaments, ganda kana kunyange cartilage.), gonads (masero epabonde emangwana), itsvo kana circulatory system.

Embryogenesis inopfuura nhanho itsva yakakosha mukati mevhiki yechina yekuzvitakura (masvondo matanhatu). Iwo maprimitive layers anobva ashanduka kuita cylindrical C-shaped structure, pasi pekuita kwekupetwa kwe embryonic disc. Izvi delimitation ye embryo, chiitiko chinobvumira kutenderedzwa kwayo maererano nemaappendages uye nekudaro kufanofananidzira ramangwana rayo, inoitika mumatanho maviri:

• Pakukotama munzira yakachinjika, remangwana kumashure kweembryo, panguva ino inotsanangurwa se dorsal protrusion, inooneka, vhoriyamu yeamniotic cavity inowedzera, embryo nemaappendages ayo anozvipeta.
• Munguva ye longitudinal inflection, nzvimbo dze cranial uye caudal dze embryo dzinoungana

Yakatsanangurwa zvakanaka, ikozvino yayangarara mu amniotic cavity, embryo inoramba ichikura:

mabuds emakumbo ekumusoro anooneka, mwoyo unotanga kurova, yekutanga 4-12 somite inoonekwa padivi rayo.

Embryonic chikamu uye organogenesis

Kubva pamwedzi wechipiri wemimba, nhengo dze embryo dziri kukura nekukurumidza. Izvi zvinonzi organogenesis.

• Pasi pekuita kwekukurumidza kukura kwenheyo system, cephalic pole ye embryo (musoro wayo) inokura uye inoshanduka. Mukati, forebrain (forebrain) inopatsanurwa muzvikamu zviviri zvakapoteredza vhiki yechishanu yekuzvitakura. Chimwe chiitiko chinocherechedzwa panguva ino: ratidziro yenhengo dzekunzwa.
• Musvondo rechitanhatu, iri pakutanga kwenzira yekunze yekunzwa kuti ionekwe, senge vertebrae, ikozvino yakaiswa yakatenderedza musana, uye kumashure tsandanyama. Mamwe maitiro e "embryo" panguva ino: dumbu rayo rine chimiro chekupedzisira uye masero ekutanga epabonde ari panzvimbo.
• Pamasvondo makumi maviri nemana nepamuviri, nhengo dzinoramba dzichikura uye ma-inter-digital grooves anoonekwa pamaoko nezvigunwe apo musculature yemwoyo inosiyana.

Pakupera kwevhiki rechisere, organogenesis inenge yapera. Nhengo dzakasiyaniswa uye dzinofanira "kukura" panguva ye "fetus phase". Iyo embryo, kune chikamu chayo, inotora chimiro chemunhu chinowedzera: musoro wayo unosimuka, mutsipa wayo ikozvino wakaumbwa sechiso chayo uye kunyanya miromo, mhino, maziso nenzeve.

Pamasvondo mapfumbamwe ekuzvitakura (masvondo gumi nerimwe), "embryo" inova "fetus". Iyo fetal nguva, iyo inotangira kubva pamwedzi we9 wekuzvitakura kusvika pakuzvarwa kunoratidzwa pamusoro pekukura kwematishu uye nhengo. Iri zvakare panguva iyi iyo fetus inosangana nekuwedzera kukuru kwehukuru uye uremu. Muenzaniso unonyanya kutaura: kubva pa 11 cm uye 3 g pamagumo embryonic nguva, mwana wemangwana anopfuura 3 cm uye 11 g pakupera kwemwedzi we12 wemimba!