GENERAL EMBRYOLOGY 1. Development of embryology 2. Germ cell and fertilization 3. Blastocyst and implantation 4. Formation of the germ layer 5. Differentiation. - презентация

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2 GENERAL EMBRYOLOGY 1. Development of embryology 2. Germ cell and fertilization 3. Blastocyst and implantation 4. Formation of the germ layer 5. Differentiation of trilaminar germ and formation of embryo 6. Fetal membrane and placenta 7. Twins and multiple birth

3 Preembryonic period: 1st week to end of 2nd week fertilization to formation of bilaminar germ disc Embryonic period : 3rd week to end of 8th week formation of embryo Fetal period: 9th week to birth growth Perinatal stage: 26th week to 4 week after birth

4 Germ cell and fertilization Germ cell spermatozoon and ovum 1. 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 sperms 2. Ovum secondary oocyte arrested at metaphase in the second meiotic division

5 Fertilization: The process in which the spermatozoon penetrates into the ovum to form fertilized ovum. In the ampulla of oviduct

6 nucleusacrosome Penetration and release of acrosomal enzyme Cell membrane of ovum Process of fertilization Sperm bind to sperm receptor ZP-3 induce Acrosome reaction release of acrosomal enzyme

7 ovum fertilized ovum sperm

8 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 for sperm penetration

9 Contac of sperm and ovum

10 Sperm penetrate into the ovum

11 Formation of female and male pronucleus

12 Fusion of pronuclei

13 Fusion of the membrane of sperm and ovum The nucleus of sperm penetrate into ovum Formation of pronuclei Fusion of pronuclei Process of fertilization Alteration of ovum 24 h

14 2.Condition of fertilization Normal ovum Normal sperm sufficient numbers Certain time 12-24h Free reproductive tract

15 3.Significance of fertilization A new life Diploid inheritance and aberrance Sex determination

16 Formation of blastocyst and implantation Cleavage and formation of blastocyst 1. Cleavage early division of fertilized egg 2. Blastomere daughter cells from cleavage 3. Morula 12 to 16- cell stage, enclosed in the zona pellucida, like morus 4. Blastocyst about 100 blastmeres blastocoele inner cell mass and trophoblast polar trophoblast

17 Phase of cleavage Fertilized egg 2-cell stage 18~36h 4-cell stage 36~48h 8-cell stage 48~60h

18 Morula 12 to 16-cell stage The third day

19 Appearance and inner structure of blastocyst Appearance Inner structure

20 Movement of fertilized egg in the oviduct

21 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 day 1.Trophoblast proliferate and differentiate into two layers Syncytiotrophoblast outer layer, fused each other, cell boundaries disappear Cytotrophoblast inner layer cell boundaries distinct, simple cuboidal cells

22 Movement and implantation of fertilized egg

23 Implantation at 7th day Endometrium Polar trophoblast Inner cell mass Cytotrophoblast

24 2.Decidua endometrium implantation decidua decidual response Decidua basalis under the implantation site Decidua capsularis between the implantation site and the uterine lumen Decidua parietalis remaining endometrium

25 Decidua

26 Formation of germ layer Bilaminar germ disc 1.Bilaminar germ disk Inner cell mass2 layers of cell in disc (7th day) Epiblast: columnar cells adjacent to trophoblast Hypoblast: cuboidal cells adjacent to blastocoele

27 Bilaminar germ disc Epiblast Hypoblast Columnar cells Cuboidal cells Epiblast Hypoblast

28 2. Amnion 8th day epiblast amnioblast aminiotic membrane amniotic cavity amniotic fluid 3.Primary yolk sac 9th day hypoblast extraembyronic endoderm primary yolk sac

29 Bilaminar germ disc at 9th day Hypoblast Epiblast Amniotic cavity Syncytio- trophoblast Primary yolk sac

30 Bilaminar germ disc Decidua Syncytiotrophoblast Epiblast Hypoblast Primary yolk sac Amniotic cavity Cytotrophoblast

31 4. Extraembryonic mesoderm: 10th-11th day 5. Extraembryonic cavity: 12th-13th day Extraembryonic mesoderm: visceral layer parietal layer 6. Secondary yolk sac: 13th day 7. Body stalk: 14th day

32 Embryo at 10th day Primary yolk sac Extraembryonic mesoderm Germ disc Amnion

33 Bilaminar germ disc Decidua Amniotic cavity Epiblast Hypoblast Extraembryonic mesoderm Primary yolk sac Cytotrophoblast Syncytiotrophoblast

34 Embryo at 13th day Extraembryonic cavity Primary yolk sac Secondary yolk sac Body stalk

35 Bilaminar germ disc Body stalk Secondary yolk sac Extraembryonic cavity Primary stem villus Extraembryonic mesoderm Visceral layer Extraembryonic mesoderm Parietal layer

36 Trilaminar germ disc primitive streak, primitive groove 3rd week primitive node, primitive pit 3rd week 1. Endoderm: primitive groove hypoblast endoderm 2. Mesoderm primitive groove between epiblast and hypoblat mesoderm 3. Ectoderm epiblast ectoderm Formation of trilaminar germ

37 Primitive streak Epiblast Hypoblast Epiblast Hypoblast Primitive streak

38 Determine the direction of the embryo notochord Primitive node Primitive pit Primitive groove Primitive streak Significance of primitive streak

39 Hypoblast Epiblast Primitive streak Endoderm Formation of endoderm

40 Epiblast Endoderm Formation of mesoderm Mesoderm

41 Ectoderm Endoderm Mesoderm Trilaminar germ disc

42 Epiblast proliferation Primitive pit Head process Notochordal tube Neurenteric canal Notochord Significance of notochord ?

43 No mesoderm Buccopharyngeal membrane Cloacal membrane

44 Differentiation of trilaminar germ and formation of embryo Differentiation of trilaminar germ 1.Differentiation of ectoderm Neural tube blastema of CNS neural plate (18th-19th day) Neuro-epithelium (neural ectoderm): pseudostratified columnar neural groove, neural fold neural tube (closed at 22nd day)

45 Neural groove Paraxial mesoderm Intermediate mesoderm

46 Neural groove Paraxial mesoderm intermediate mesoderm

47 Neural groove Neural crest Notocord

48 1 Differentiation of ectoderm Anterior neuropore closed at 25th Posterior neuropore closed at 27th Neural tube Neural fold closed at 22nd day, from 4th somite

49 U nclosed Anterior neuropore Unclosed Posterior neuropore

50 Neural crest blastema of PNS chromaffin cell, parafollicular cell some of bone, cartilage and muscle of head Superficial ectoderm: after formation of neural tube epidermis

51 2.Differentiation of mesoderm 17th day Paraxial mesoderm somite at 20th day, from the head Dermotome dermis, hypodermis Myotome skeletal muscle, Sclerotome axial skeleton. Intermediate mesoderm urinary and reproductive system Lateral mesoderm parietal mesoderm viseral mesoderm intraembryonic coelomic cavity

52 Somite

53 Parietal mesoderm Intraembryonic coelomic cavit Visceral mesoderm Differentiation of lateral mesoderm Dermatome Sclerotome

54 Extraembryonic coelomic cavity Intraembryonic coelomic cavity Differentiation of lateral mesoderm

55 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

56 Formation of primitive gut A B

57 Parietal mesoderm Intraembryonic coelomic cavity Visceral mesoderm

58 Formation of embryonic body (4-8th week) DiscColumn folds the number of somite increase face development, formation of branchial pouch breach of buccopharyngeal membrane 5th week: upper and lower limb buds 6th week: hand and foot plates 7th week: formation of face, disappear of somite 8th week: breach of cloacal membrane 20-30th day

59 At the end of 8th week a small human

60 Fetal membrane and placenta Fetal membrane Chorion Amnion Yolk sac Allantois Umbilical cord

61 Amnion Yolk sac Umbilical cord Placenta

62 1.Chorion Secondary stem villus +chorinic plate Primary stem villus 2nd week Outer syncytiotrophoblast+ Inner cytotrophoblast C horinic plate : extraembryonic mesoderm + trophoblast

63 Secondary stem villus 3rd week Outer syncytiotrophoblast+ Intermedial extraembryonic mesoderm+ Inner cytotrophoblast Tertiary stem villus end of 3rd week, Blood vessels Anchoring villus, Free villus cytotrophoblastic cell column cytotrophoblastic shell

64 Primary stem villus at 2nd week cytotrophoblast Secondary stem villus at 3rd week extraembryonic mesoderm Tertiary stem villus at the end of 3rd week blood vessels

65 Anchoring villus Free villus Cytotrophoblastic shell Cytotrophoblastic column Stem villus

66 Evolvement of chorion Chorion laeveChorion frondosum 6th weeks Chorion laeve adjacent to decidua capsularis Chorion frondosum adjacent to decidua basalis

67 Abnormility of chorion Hydatidiform Hydatidiform Chorion carcinoma Chorion carcinoma Picture

68 Hydatidiform

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71 Chorion carcinoma

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74 2. Yolk sac 5th-6th week, atresia Abnormality: Meckels diverticulum Umbilical fistula Primitive blood cells Primordial germ cells

75 3. Amnion amniotic membrane: mm amniotic epithelium + extraembryonic mesoderm amniotic fluid: ml abnormality: 500 ml, oligohydramnios 2000 ml, polyhydramnios protection

76 4. Allantois degeneration Abnormality: Urachal fistula 2 pairs of blood vessel 1 umbilical vein 1 pair of umbilical artery

77 5. Umbilical cord 50 cm (CT, umbilical vein umbilical artery, degenerated yolk sac and allantois) covered with amniotic membrane Abnormality: 80 cm, 35 cm connect fetus with placenta

78 Fetal membrane

79 Placenta 1.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)

80 Umbilical artery Umbilical vein Spiral artery Uterus vein Decidua bsalis Placenta septa

81 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

82 Syncytiotrophoblast Cytotrophoblast Basal lamina Connective tissue Basal lamina Endothelium NutrimentMetabolic product Fetal membrane Blood of mother

83 3.Function Substance exchange O 2, nutriment, CO 2, waste Hormone Human chorionic gonadotropin, HCG; Human placental lactogen, HPL; Human placental progesterone, HPP, Human placental estrogen, HPE

84 Function Substance exchange Substance exchange Placenta Capillary of fetusBlood of mother 2 Nutriment water salt others 2 Metabolic waste Placenta membrane

85 Function Barrier Barrier Placenta Capillary of fetusBlood of mother s Placenta barrier No way Most of microorganism

86 Function Barrier Barrier Placenta Capillary of fetusBlood of mother Most of drugs Placenta barrier Most of microorganism Some of microorganism

87 Function Endocrine Placenta Hormone Function AppearanceFastigium HCG Corpus luteum Pregnancy 3rd week8th week HCS Mammary gland 2nd month8th month HPE Corpus luteum4th month8th month HPP Corpus luteum 4th month8th month

88 Twins and multiple birth 1.Twins monozygotic twins dizygotic twins

89 2. Multiple birth monozygotic multiple birth polyzygotic multiple birth mixed multiple birth

90 Dizygotic twins Blastocyst 2 Amnion 2 Chorion 2 Placenta

91 Monozygotic twins separation of blastomere, of ICM, of primitive streak Blastocyst 2 ICM 2 primitive streak 2 Amnion 2 Amnion 1 Amnion 2 Chorion 1 Chorion 1 Chorion 2 Placenta 1 Placenta 1 Placenta