Embryology_4_Implantation,_Trophoblast_and_Chorion_Prof_Osama.pdf

Field of Medicine Medicine And Surgery Program General Embryology – 4 Trophoblast and Chorion Prof. Usama Hussein Date : 21 / 11 /2023 ILOs: by the end of this lecture, you will be able to: 1. Describe implantation & its steps. 2. Locate the normal & abnormal sites of implantation....

Field of Medicine Medicine And Surgery Program General Embryology – 4 Trophoblast and Chorion Prof. Usama Hussein Date : 21 / 11 /2023 ILOs: by the end of this lecture, you will be able to: 1. Describe implantation & its steps. 2. Locate the normal & abnormal sites of implantation. 3. Describe the decidua & its parts. 4. Define layers of trophoblast, extraembryonic mesoderm & chorion 5. List the types of chorionic villi & describe their fate blastocyst )blastula(  decidua blastocyst )blastula(  myometrium decidua basalis P decidua capsularis decidua parietalis uterine cavity A trophoblast maternal blood vessels inner cell mass blastocoele amnion primary yolk sac )exocoelomic cavity(  amnion amniogenic cells epiblast hypoblast primary yolk sac )exocoelomic cavity(  A Y.S 2ry yolk sac ectoderm epiblast A Y.S endoderm bilaminar embryonic disc (2nd week)  ectoderm syncytiotrophoblast cytotrophoblast A extraembryonic YS )primary( mesoderm endoderm maternal blood blood vessels amnion syncytiotrophoblast ectoderm cytotrophoblast decidua extraembryonic )primary( mesoderm endoderm 2ry yolk sac  syncytiotrophoblast cytotrophoblast A extraembryonic YS )primary( mesoderm  body ( connecting ) chorionic villi stalk inner chorion )splanchnic( layer outer )somatic( layer chorionic vesicle extraembryonic coelom  beginning of maternal blood a chorionic villus blood vessels amnion decidua body ( connecting ) basalis stalk ectoderm syncytiotrophoblast endoderm cytotrophoblast splanchnic layer of extraembryonic mesoderm somatic layer of extraembryonic mesoderm extraembryonic coelom decidua 2ry yolk sac capsularis  body ( connecting ) chorionic villi stalk chorion splanchic layet somatic layer extraembryonic coelom  primary chorionic villus lacunae of maternal blood in the intervillous space secondary chorionic villus  cytotrophoblastic shell tertiary chorionic villus lacunae of maternal blood in the intervillous space placental barrier to embryo  maternal blood blood vessels decidua lacunae of maternal blood in the intervillous space somatic layer of extraembryonic mesoderm cytotrophoblast syncytiotrophoblast primary chorionic villus  maternal blood blood vessels decidua cytotrophoblastic shell lacunae of maternal blood in the intervillous space somatic layer of cytotrophoblast syncytiotrophoblast extraembryonic mesoderm secondary chorionic villus  maternal blood decidua blood vessels cytotrophoblastic shell lacunae of maternal blood syncytiotrophoblast somatic layer of extraembryonic mesoderm cytotrophoblast tertiary blood chorionic vessels placental barrier fetal villus arteries  cytotrophoblastic shell tertiary chorionic villus lacunae of maternal blood in the intervillous space placental barrier to embryo  D. basalis D. parietalis tertiary chorionic villus somatic layer amnion ectoderm 2ry yolk sac splanchnic layer body stalk endoderm extraembryonic coelom D. capsularis  chorion frondosum chorion laeve tertiary chorionic villi  chorion frondosum chorion laeve tertiary chorionic villi