General embryology Langman's medical embryology, 9th ed Jun zhou(周俊) School of medicine, Zhejiang University 20121225
General embryology Jun Zhou (周俊） School of Medicine, Zhejiang University 20121225 Langman’s Medical Embryology, 9th Ed
a science which study the processes and regulations of development of human fetus. from 1 cell(zygote)to(5-7) x10 cells) oIn general the length of pregnancy is considered to be 280 days or 40 weeks after the onset of the last menstruation, or more accurately, 266 days or 38 weeks after fertilization Onset of Fertilization last M.c 14 days 266 days abor 280 days
Fertilization 14 days Onset of last M.C. 266 days 280 days ◆ a science which study the processes and regulations of development of human fetus.(from 1 cell (zygote) to (5-7) x1012 cells) ◆In general the length of pregnancy is considered to be 280 days or 40 weeks after the onset of the last menstruation, or more accurately, 266 days or 38 weeks after fertilization. Labor
Total 38 weeks. e Preembryonic period: before 2 weeks .Embryonic period: 3-8 Weeks e Fetal period after 9 weeks
Preembryonic period: before 2 weeks Embryonic period: 3-8 weeks Fetal period: after 9 weeks Total 38 weeks:
o Preembryonic period: before 2 weeks o Embryonic period: 3-8 Weeks 3周 4周 5周 6周 7周 周 e Fetal period: after 9 weeks9B16B 20363周
Embryonic period: 3-8 weeks Fetal period: after 9 weeks Preembryonic period: before 2 weeks
Fertilization Definition: the process by which the male and female gametes(sperm and ovum) unite to give rise to zygote place: in the ampullary region of the oviduct
Fertilization ▪ Definition: the process by which the male and female gametes(sperm and ovum) unite to give rise to zygote ▪place: in the ampullary region of the oviduct
精相题O 卵细麗 初级精母 D(0X I 细胞46.XY 初级柳母细慰 D (届6,XⅩ Puting apart of 丹脱○ Anaphase of 1st 精子 细胞 22X23,Y23x123Y 次级卵母@极体 细胞23X V人 极体 ells resulted from 明f 23,X conditions: 1) maturation of oocyte 2)maturation of spermatozoa
conditions: 1) maturation of oocyte 2) maturation of spermatozoa
3capacitation and acrosome reaction of spermatozoa: R5 capacitation factor; secreted by epi. cells of oviduct, capacity of releasing acrosome enzymes 4)quality and quantity of spermatozoa 2-6ml,100,000,000/m, 30%;or capacity for mobile< 70% 5)meeting of sperm and ovum within 24 hrs
3) capacitation and acrosome reaction of spermatozoa: R5 • capacitation factor: secreted by epi. cells of oviduct, capacity of releasing acrosome enzymes 4) quality and quantity of spermatozoa: • 2-6 ml, 100,000,000/ml, • 30%; or capacity for mobile< 70% 5) meeting of sperm and ovum within 24 hrs
Processes of fertilization Corona radiata cells Phase i Phase1 penetrate the corona radiata, Polar body acrosomal release ● Phase ii Acrosome nner acrosomal -ZP with receptors- zona pellucida nucleus Secondary oocyte in 2nd meiotic spongy- the release of local division enzymes Fusion oocyte and sperm cell membranes ● Phase il Success formation of zygote
Processes of fertilization: •Phase I –penetrate the corona radiata, acrosomal release •Phase II –ZP with receptors – zona pellucida spongy – the release of local enzymes •Phase III –Success formation of zygote
Entry/-response 1 Cortical or zona reactions Compaction - impermeable to more sperm 2)Oocyte finishes 2nd meiotic division 3 Female/ Male pronucleus Metabolic activation of the egg Results of fertilization Diploid Genetic sex Cleavage
• Entry – response 1) Cortical or zona reactions - Compaction - impermeable to more sperm 2) Oocyte finishes 2nd meiotic division 3) Female /Male pronucleus 4) Metabolic activation of the egg • Results of fertilization – Diploid – Genetic sex – Cleavage
Cleavage o Mitosis and cytoplasmic division ● Blastula- blastomeres morula rinner cell mass embryoblast outer cell rim trophoblasts Papered felice ● Blastocyst Blastocoele hfed fram Before W The cells of morula secrete fluid re and Pesaud. 190B W Saud Zona pellucid disappears
Cleavage •Mitosis and cytoplasmic division •Blastula - blastomeres •Morula –inner cell mass •embryoblast –outer cell rim •trophoblasts •Blastocyst –Blastocoele –The cells of morula secrete fluid –Zona pellucide disappears