Embryology Week 2

Question 1

In day 8 where does the blastocyst embed itself in?

Answer 1

endometrium - partially

Question 2

What is cytotrophoblast?

Answer 2

inner layer of mononucleated cells

Question 3

What is syncytitrophoblast?

Answer 3

outer multinucleated zone without distinct boundaries - erodes maternal tissue

Question 4

What happens in the syncytiotrophoblast?

Answer 4

cells in cytotrophoblast divide and migrate into synctiotrophoblast where they fuse + lose their individual membranes

Question 5

What 2 different layers form the embryoblast?

Answer 5

1. hypoblast - small cuboidal cells adjacent to blastocyst cavity 2. epiblast - columnar cells adjacent to amniotic cavity

Question 6

Cells of each germ layer are known as?

Answer 6

bilaminar germ disc - form a flat disc

Question 7

Where does the small cavity appear?

Answer 7

within epiblast

Question 8

What does the cavity enlarge to become?

Answer 8

amniotic cavity

Question 9

What are amnioblasts?

Answer 9

epiblast cells adjacent to cytotrophoblast

Question 10

What is their function?

Answer 10

slide 8

Question 11

Where do the vacuoles appear on day 9 and 10?

Answer 11

slide 9

Question 12

Describe what happens at the lacunar stage?

Answer 12

slide 9

Question 13

What is the Heuser’s membrane?

Answer 13

slide 10

Question 14

What surrounds it?

Answer 14

slide 10

Question 15

What happens to the blastocyst at days 11 and 12

Answer 15

slide 10

Question 16

What are sinusoids?

Answer 16

slide 11

Question 17

What is uteroplacental circulation?

Answer 17

slide 11

Question 18

What is extraembryonic mesoderm?

Answer 18

slide 12

Question 19

What is the chorionic cavity?

Answer 19

slide 13

Question 20

What are the 2 parts of the extraembryonic mesoderm?

Answer 20

slide 15

Question 21

What are villous structures ?

Answer 21

slide 15

Question 22

Where do the cells produced by the hypoblast move?

Question 23

What forms the secondary yolk cavity?