Fetal Membranes, Placenta and Birth defects Jun zhou(周俊) School of Medicine, Zhe Jiang university 20160113
Fetal Membranes, Placenta and Birth defects Jun Zhou（周俊） School of Medicine, ZheJiang University 20160113
Fetal membrane -overview Originate from blastocyst, don'tsoxM Amnion Embryo participate in the formation of yOlk sac embryo Charion Including )Chorion 2)Amnion 3Yolk sac 4)Allantois uMbilical cord Extraembryonic Membranes
Fetal membrane — overview •Originate from blastocyst, don’t participate in the formation of embryo •Including: 1) Chorion 2) Amnion 3) Yolk sac 4) Allantois 5) Umbilical cord
Chorion . Formed by trophoblast +extraembryonic mesoderm e Chorion frondosum (bushy chorion)-embryonic pole o Chorion laeve (smooth chorion)-abembryonic pole Decidua Chorion frondosum connecting ChorionIc cavity Yolk sac -chorionic Decidua Chorion laeve
Chorion •Formed by trophoblast +extraembryonic mesoderm •Chorion frondosum (bushy chorion)- embryonic pole •Chorion laeve (smooth chorion)- abembryonic pole
Development ofⅷi‖l Week 2 to week 3 Primary vill: cytotrophoblast+syncytiotrophoblast Secondary villi: extraembryonic mesoderm enter the primary Tertiary villi extraembryonic mesoderm =>CT+BV 层 駐外中胚层 syncytiotrophoblast Mesoderm core lous capillary c
Development of villi Week 2 to week 3 ▪ Primary villi: cytotrophoblast+syncytiotrophoblast ▪ Secondary villi: extraembryonic mesoderm enter the primary villi ▪ Tertiary villi: extraembryonic mesoderm =>CT+BV
cytotrophoblastic connective tissue tertiar villUS Intervillous space ater blood materna SInus capillaries
Function of chorion 1)Exchange of metabolite portion of placenta( chorion frondosum) 2)Hormone production human chorionic gonadotropin (Hcg early indication of pregnancy)
Function of Chorion 1) Exchange of metabolite: portion of placenta (Chorion frondosum) 2) Hormone production: human chorionic gonadotropin (HCG) ( Early indication of pregnancy)
Amnion .Amniotic membrane: amniotic epi. extraembryonic mesoderm aMniotic fluid Produce: 1 )amniotic cells 2)infusion of fluid from maternal blood urine output from the fetus 4)pulmonary secretions Output: 1 absorbed by amniotic cells 2)fetus swallow o30 ml---10 weeks 450 ml---20 weeks 800-1000 m ---37 weeks---circulate
Amnion •Amniotic membrane: amniotic epi.+ extraembryonic mesoderm •Amniotic fluid: Produce:1)amniotic cells 2) infusion of fluid from maternal blood 3) urine output from the fetus 4) pulmonary secretions Output: 1) absorbed by amniotic cells 2) fetus swallow •30 ml--- 10 weeks •450 ml--- 20 weeks •800-1000 ml --- 37 weeks---circulate
Amnion- Fluid Functions Vie ghor Mechanically cushion Protect from fetus adhesion Movement Maintain tem p a Abnormalities 1)too much(polyhydramnios Decidua bosn >2000ml abnormal digestive system or Lerne cave CNS Amnion honore sa esophageal atresia anencephaly 2)too little(oligohydramnios) Mucous plue Mucous phag <500ml Abnormal urinary system poor development of kidney urethra atresia
Amnion - Fluid ▪ Functions ➢ Mechanically cushion ➢ Protect from fetus adhesion ➢ Movement ➢ Maintain Temp ▪ Abnormalities 1) too much (polyhydramnios) >2000 ml Abnormal digestive system or CNS - esophageal atresia - anencephaly 2) too little (oligohydramnios) <500 ml Abnormal urinary system - poor development of kidney - urethra atresia
Yolk sac and Allantois Respiratory a Yolk sac Heart Liver bud Primitive Gut Duodenum Vitellin >3rd week, Germ Cells >3rd to 6th week membrane Blood island Allantois sto. Chsd Develmmaet Be Cepyighdo tw Meoraw-hsa cemen的A构eed The placenta and the Caudal extension of Umbilical cord hindgut Allantoic a pairs Uterus Umbilical Allantoic V pairs cord Umbilic allantois Umbili cord Umbilical Umbilical vessels n Fetal portion Maternal of placenta portion of 2A+1V acen
Yolk sac and Allantois ▪ Yolk sac ➢ Primitive Gut ➢ 3 rd week, Germ Cells ➢ 3 rd to 6th week, Blood island ▪ Allantois ➢ Caudal extension of hindgut ➢ Allantoic A pairs ➢ Allantoic V pairs Umbilical vessels 2A+1V
Umbilical cord Folding -a purse string Chronic cavity Chorion Chorionic plate roca Child closure The placenta and the Umbilical cord > Amnion membrane covered >Cord muCOUs CT.3 Uterus Umbilical vessels yolk sac allantois Umbilical At birth 50-60 cm. 2cm diameter Umbilical cord Umbilical veIn Long -knots Placenta Fetal portion Maternal of placenta portion of Short- placenta detachment placenta
Umbilical Cord ▪ Folding – a purse string closure ➢ Amnion membrane covered ➢ Cord: mucous CT, 3 vessels,yolk sac ,allantois ➢ At birth, 50-60 cm, 2cm diameter ➢ Long – knots ➢ Short – placenta detachment
