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The human embryonic period runs until the end of the eighth week of gestation. It is during this period that the major structures begin to develop. Only the circulation and the heart is running at the moment. After this period (8 weeks), the human fetus is called During the fetal period, there is a process of cell differentiation to specialized tissues and organs, enabling recognize eyes, nose, arms and legs. See how the zygote develops! The development of a new human being begins with fertilization, or after contact of a sperm and an egg, which occurs usually in the ampulla of the uterine tube, forming the zygote. Walking through fallopian tube toward the uterus, the zygote undergoes cleavage (several mitotic cell divisions), being composed of smaller cells, the blastomeres. Around the third day after fertilization containing a ball 12 or more blastomeres, the morula enters the uterus. After the morula have reached the uterus, uterine fluid begins to receive, emerging small fluid-filled spaces. Some cells remain in the poles, forming a button-shaped grouping. This phase is referred to as a blastocyst. At the end of the first week, the blastocyst is introduced into the endometrium. Biology Mitotic division Division that occurs in somatic cells, which originate from two daughter cells identical to the original. Endometrium Membrane that lines the uterine cavity.
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Embrionalnim rok traje do kraja osmog tjedna trudnoće. To je razdoblje u kojem se glavni strukture počinju razvijati. Samo cirkulaciju i srce radi u ovom trenutku. Nakon tog razdoblja (8 tjedana), ljudski fetus zove Tijekom fetalnog razdoblja, postoji proces diferencijacije stanica u specijaliziranim tkivima i organima, što omogućuje prepoznati oči, nos, ruke i noge. Pogledajte kako zigota razvija! Razvoj novog ljudskog bića počinje s oplodnjom, ili nakon kontakta s sperme i jajeta, koja se javlja obično u Vaterovoj u jajovodu, formiranje zigota. Šetnja kroz jajovod prema maternici, zigota prolazi dekolte (nekoliko mito podjela stanica), koji se sastoji od manjih stanica, blastomeres. Oko trećeg dana nakon oplodnje sadrži loptu 12 ili više blastomeres, morula ulazi u maternicu. Nakon što su postigli morula maternice, maternice tekućina počne primati, nastajanju male prostore ispunjene tekućinom. Neke stanice ostaju na polovima, stvarajući u obliku gumba grupiranje. Ova faza se naziva blastociste. Na kraju prvog tjedna, blastocista se uvodi u endometrij. Biologija Mitotskim podjelu Odjel koji se javlja u somatskim stanicama, koje potječu iz dvije stanice kćeri identičan izvorniku. Endometrij Membrana koja oblaže šupljine maternice.