绪论胚胎学-GENERAL-EMBRYOLOGY-组织学和胚胎学

1、GENERAL EMBRYOLOGY1. Development of embryology2. Germ cell and fertilization3. Blastocyst and implantation4. Formation of the germ layer5. Differentiation of trilaminar germ and formation of embryo6. Fetal membrane and placenta7. Twins and multiple birth第一页，共九十四页。Preembryonic period: 1st week to end

2、 of 2nd week fertilization to formation of bilaminar germ discEmbryonic period: 3rd week to end of 8th week formation of embryoFetal period: 9th week to birth growthPerinatal stage: 26th week to 4 week after birth第二页，共九十四页。 Human ？Plant Animal第三页，共九十四页。Development of embryology Semen+menstration Har

3、vey, 1651: All life from oocyte Malpighi, 1675: A micro-chicken in an egg Leewenhoek, 1677 : A micro-human in a spermAristotle, B.C 384-322第四页，共九十四页。Haeckel, 1868 Biogenetic lawSpemann, 1869-1941 Experimental embryologyWilmut,1997 Dolly第五页，共九十四页。Germ cell and fertilizationGerm cell spermatozoon and

4、ovum1. Spermatozoon Capacitation：In female reproductive tract, the sperms were enabled to bind to the zona pellucida receptors. removal of glycoproteins (decapacitation factor) which cover the sperms2. Ovum secondary oocyte arrested at metaphase in the second meiotic division第六页，共九十四页。Fertilization:

5、 The process in which the spermatozoon penetrates into the ovum to form fertilized ovum. In the ampulla of oviduct第七页，共九十四页。nucleusacrosomePenetration and release of acrosomal enzymeCell membrane of ovumProcess of fertilizationSperm bind to sperm receptor ZP-3 induceAcrosome reaction：release of acro

6、somal enzyme第八页，共九十四页。ovumfertilized ovumsperm第九页，共九十四页。The second meiotic division of the secondary oocyte is rapidly lifted and the second polar body is released, leaving a haploid female nucleus.Zona reaction: Cortical granulesperivitelline space degrade ZP-3, alteration of zona pellucida barrier

7、 for sperm penetration第十页，共九十四页。Contac of sperm and ovum第十一页，共九十四页。Sperm penetrate into the ovum第十二页，共九十四页。Formation of female and male pronucleus 第十三页，共九十四页。Fusion of pronuclei第十四页，共九十四页。 Fusion of the membrane of sperm and ovum The nucleus of sperm penetrate into ovum Formation of pronuclei Fusion

8、 of pronuclei Process of fertilization Alteration of ovum24 h第十五页，共九十四页。2.Condition of fertilization Normal ovum Normal sperm sufficient numbers Certain time 12-24h Free reproductive tract第十六页，共九十四页。3.Significance of fertilization A new life Diploid inheritance and aberrance Sex determination第十七页，共九

9、十四页。Formation of blastocyst and implantationCleavage and formation of blastocyst1. Cleavage： early division of fertilized egg2. Blastomere：daughter cells from cleavage3. Morula：12 to 16- cell stage, enclosed in the zona pellucida, like morus4. Blastocyst：about 100 blastmeres blastocoele、inner cell m

10、ass and trophoblast polar trophoblast第十八页，共九十四页。Phase of cleavage Fertilized egg2-cell stage1836h4-cell stage3648h8-cell stage4860h第十九页，共九十四页。Morula12 to 16-cell stageThe third day第二十页，共九十四页。Appearance and inner structure of blastocystAppearanceInner structure第二十一页，共九十四页。Movement of fertilized egg i

11、n the oviduct第二十二页，共九十四页。Implantation (imbed) The process by which the blastocyst settles into endometrium. 6th day to 11th day Fundus and body of uterus zona pellucida disappear at the 5th day1.Trophoblast：proliferate and differentiate into two layersSyncytiotrophoblast：outer layer, fused each othe

12、r, cell boundaries disappearCytotrophoblast：inner layer， cell boundaries distinct, simple cuboidal cells第二十三页，共九十四页。Movement and implantation of fertilized egg第二十四页，共九十四页。Implantation at 7th dayEndometriumPolar trophoblastInner cell massCytotrophoblast 第二十五页，共九十四页。2.Decidua： endometrium implantation

13、 decidua decidual responseDecidua basalis：under the implantation siteDecidua capsularis：between the implantation site and the uterine lumenDecidua parietalis：remaining endometrium第二十六页，共九十四页。Decidua第二十七页，共九十四页。Formation of germ layer Bilaminar germ disc1.Bilaminar germ disk： Inner cell mass2 layers

14、of cell in disc (7th day) Epiblast: columnar cells adjacent to trophoblast Hypoblast: cuboidal cells adjacent to blastocoele 第二十八页，共九十四页。Bilaminar germ discEpiblastHypoblastColumnar cellsCuboidal cellsEpiblastHypoblast第二十九页，共九十四页。2. Amnion：8th day epiblast amnioblast aminiotic membrane amniotic cavi

15、ty amniotic fluid3.Primary yolk sac： 9th day hypoblast extraembyronic endoderm primary yolk sac第三十页，共九十四页。Bilaminar germ disc at 9th dayHypoblastEpiblastAmniotic cavitySyncytio-trophoblastPrimary yolk sac第三十一页，共九十四页。Bilaminar germ discDecidua SyncytiotrophoblastEpiblastHypoblastPrimary yolk sacAmnio

16、tic cavityCytotrophoblast第三十二页，共九十四页。 4. Extraembryonic mesoderm: 10th-11th day 5. Extraembryonic cavity: 12th-13th day Extraembryonic mesoderm: visceral layer parietal layer6. Secondary yolk sac: 13th day7. Body stalk: 14th day第三十三页，共九十四页。Embryo at 10th dayPrimary yolk sacExtraembryonic mesodermGer

17、m discAmnion第三十四页，共九十四页。Bilaminar germ discDeciduaAmniotic cavityEpiblastHypoblastExtraembryonic mesodermPrimaryyolk sacCytotrophoblastSyncytiotrophoblast第三十五页，共九十四页。Embryo at 13th dayExtraembryonic cavityPrimary yolk sac Secondary yolk sacBody stalk第三十六页，共九十四页。Bilaminar germ discBody stalkSecondary

18、 yolk sacExtraembryonic cavityPrimary stem villusExtraembryonic mesodermVisceral layerExtraembryonic mesodermParietal layer第三十七页，共九十四页。Trilaminar germ disc primitive streak, primitive groove 3rd week primitive node, primitive pit 3rd week1. Endoderm: primitive groove hypoblast endoderm2. Mesoderm： p

19、rimitive groove between epiblast and hypoblat mesoderm3. Ectoderm：epiblast ectodermFormation of trilaminar germ第三十八页，共九十四页。Primitive streak EpiblastHypoblast EpiblastHypoblastPrimitive streak第三十九页，共九十四页。Determine the direction of the embryonotochordPrimitive node Primitive pit PrimitivegroovePrimiti

20、vestreakSignificance of primitive streak第四十页，共九十四页。Hypoblast Epiblast Primitive streakEndodermFormation of endoderm第四十一页，共九十四页。EpiblastEndoderm Formation of mesodermMesoderm第四十二页，共九十四页。Ectoderm EndodermMesodermTrilaminar germ disc第四十三页，共九十四页。EpiblastproliferationPrimitive pitHeadprocessNotochordal t

21、ubeNeurenteric canalNotochordSignificance of notochord ?第四十四页，共九十四页。 No mesodermBuccopharyngeal membraneCloacal membrane第四十五页，共九十四页。Differentiation of trilaminar germ and formation of embryoDifferentiation of trilaminar germ1.Differentiation of ectoderm Neural tube：blastema of CNS neural plate (18th

22、-19th day) Neuro-epithelium (neural ectoderm): pseudostratified columnar neural groove , neural fold neural tube (closed at 22nd day)第四十六页，共九十四页。 Neural groove Paraxial mesoderm Intermediate mesoderm第四十七页，共九十四页。 Neural groove Paraxial mesoderm intermediate mesoderm第四十八页，共九十四页。Neural grooveNeural cre

23、stNotocord第四十九页，共九十四页。1、Differentiation of ectoderm Anterior neuropore closed at 25thPosterior neuropore closed at 27thNeural tubeNeural fold closed at 22nd day, from 4th somite第五十页，共九十四页。 Unclosed Anterior neuropore Unclosed Posterior neuropore第五十一页，共九十四页。Neural crest： blastema of PNS chromaffin ce

24、ll, parafollicular cell some of bone, cartilage and muscle of headSuperficial ectoderm: after formation of neural tube epidermis第五十二页，共九十四页。2.Differentiation of mesoderm 17th dayParaxial mesoderm：somite at 20th day, from the head Dermotome dermis, hypodermis Myotome skeletal muscle, Sclerotome axial

25、 skeleton.Intermediate mesoderm：urinary and reproductive systemLateral mesoderm：parietal mesoderm， viseral mesoderm， intraembryonic coelomic cavity 第五十三页，共九十四页。Somite第五十四页，共九十四页。Parietal mesoderm Intraembryonic coelomic cavitVisceral mesodermDifferentiation of lateral mesodermDermatomeSclerotome第五十五

26、页，共九十四页。Extraembryonic coelomic cavityIntraembryonic coelomic cavityDifferentiation of lateral mesoderm第五十六页，共九十四页。3. Differentiation of endoderm Epithelium of primitive gut epithelium of digestive tract, digestive gland, respiratory tract and lung Primitive pharynx 5 pairs of pharyngeal pouch第五十七页，

27、共九十四页。 Formation of primitive gutAB第五十八页，共九十四页。Parietal mesodermIntraembryonic coelomic cavityVisceral mesoderm第五十九页，共九十四页。Formation of embryonic body (4-8th week)DiscColumn folds the number of somite increase face development, formation of branchial pouch breach of buccopharyngeal membrane5th week:

28、 upper and lower limb buds6th week: hand and foot plates7th week: formation of face, disappear of somite8th week: breach of cloacal membrane20-30th day第六十页，共九十四页。At the end of 8th weeka small human 第六十一页，共九十四页。Fetal membrane and placentaFetal membrane Chorion Amnion Yolk sac Allantois Umbilical cord

29、第六十二页，共九十四页。AmnionYolk sacUmbilical cordPlacenta第六十三页，共九十四页。1.Chorion： Secondary stem villus +chorinic plate Primary stem villus：2nd week Outer syncytiotrophoblast+ Inner cytotrophoblast Chorinic plate : extraembryonic mesoderm + trophoblast第六十四页，共九十四页。 Secondary stem villus：3rd week Outer syncytiot

30、rophoblast+ Intermedial extraembryonic mesoderm+ Inner cytotrophoblast Tertiary stem villus：end of 3rd week, Blood vessels Anchoring villus, Free villus cytotrophoblastic cell column cytotrophoblastic shell第六十五页，共九十四页。Primary stem villus：at 2nd week，cytotrophoblast Secondary stem villus：at 3rd week，

31、extraembryonic mesoderm Tertiary stem villus：at the end of 3rd week，blood vessels第六十六页，共九十四页。 Anchoring villusFree villusCytotrophoblastic shellCytotrophoblastic columnStem villus第六十七页，共九十四页。Evolvement of chorion Chorion laeveChorion frondosum6th weeksChorion laeve：adjacent to decidua capsularisChor

32、ion frondosum： adjacent to decidua basalis第六十八页，共九十四页。Abnormility of chorion： Hydatidiform Chorion carcinoma Picture 第六十九页，共九十四页。Hydatidiform第七十页，共九十四页。Hydatidiform第七十一页，共九十四页。Hydatidiform第七十二页，共九十四页。Chorion carcinoma第七十三页，共九十四页。Chorion carcinoma第七十四页，共九十四页。Chorion carcinoma第七十五页，共九十四页。 2. Yolk sac：

33、5th-6th week, atresia Abnormality: Meckels diverticulum Umbilical fistula Primitive blood cells Primordial germ cells 第七十六页，共九十四页。3. Amnion： amniotic membrane: 0.2-0.5mm amniotic epithelium + extraembryonic mesoderm amniotic fluid: 500-1000ml abnormality: 500 ml, oligohydramnios 2000 ml, polyhydramn

34、ios protection第七十七页，共九十四页。4. Allantois：degeneration Abnormality: Urachal fistula 2 pairs of blood vessel 1 umbilical vein 1 pair of umbilical artery第七十八页，共九十四页。5. Umbilical cord：50 cm (CT, umbilical vein， umbilical artery, degenerated yolk sac and allantois) covered with amniotic membrane Abnormalit

35、y: 80 cm, 35 cm connect fetus with placenta第七十九页，共九十四页。Fetal membrane第八十页，共九十四页。Placenta1.Placenta: Chorion frondosum + Decidua basalis disk: 15-20cm Sandwich: chorinic plate (fetus) villi basal plate (mother) basal plate: decidua + cytotrophoblastic shell placental septa cotyledon (incomplete) 第八十一

36、页，共九十四页。Umbilical arteryUmbilical veinSpiral arteryUterus veinDecidua bsalisPlacenta septa第八十二页，共九十四页。2.Placental membrane： Structure between the blood of mother and fetus Syncytiotrophoblast； Cytotrophoblast and its basal lamina； Connective tissue； Endothelium and its basal lamina protection第八十三页，共

37、九十四页。胎儿血SyncytiotrophoblastCytotrophoblast Basal laminaConnective tissueBasal laminaEndotheliumNutrimentMetabolic productFetal membraneBlood of mother第八十四页，共九十四页。3.Function： Substance exchange O2, nutriment, CO2, waste Hormone Human chorionic gonadotropin, HCG; Human placental lactogen, HPL; Human placental progesterone, HPP, Human placental estrogen, HPE第八十五页，共九十四页。Function Substance exchangePlacentaCapillary of fetusBloo