Second Week of Development Flashcards Preview

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Flashcards in Second Week of Development Deck (17):
1

Trophoblast forms 2 layers

inner layer of cells- cytotrophoblast
outer layer- syncytiotrophoblast

2

Embryoblast differentiates to form a bilaminar embryonic disc of 2 layers

The epiblast (thicker) and the hypoblast

3

A small cavity appears in the epiblast that enlarges to form what?

the amniotic cavity

4

What does the amnion formed by amnioblasts do?

encloses the amniotic cavity

5

Days 9-10 the hypoblast now becomes what?

the exocoelomic cavity

6

The exocoelomic membrane and exocoelomic cavity are modified to form what?

the primitive yolk sac

7

When does the blastocyst become fully embedded in the endometrium?

Day 10, site closed by fibrin coagulum

8

When is uteroplacental circulation established?

Days 11-12

9

Formation of the primary villi

the cells of the cytotrophoblast proliferate and penetrate into syncytiotrophoblast forming cellular columns that are surrounded by syncytia

10

Where does the exchange of materials (oxygen and nutrients) between the blood of the mother and the embryo take place?

through the walls of branch chorionic villi

11

Where is the embryo, amniotic sac, and umbilical vesicles suspended?

the chorionic cavity

12

What does the syncytotrophoblat produce?

hCG which by the end of the 2nd week can be detected by a pregnancy test

13

Hydatidiform mole

trophoblast forms placental membranes but there is no embryonic development

14

Placenta previa

placenta bridges the internal os of the cervix causing severe, life-threatening bleeding in late pregnancy and during delivery

15

Placenta accreta

abnormal adherence of the placenta to the myometrium

16

Placenta percreta

chorionic villi penetrate the myometrium all the way to the perimetrium

17

Ectopic pregnancy

implantation outside the uterus