Embryology

Question 1

what is the morula?

Answer 1

16+ blastomere cells

Question 2

what is a blastocyst?

Answer 2

200-300 cells

Question 3

what makes up the blastocyst?

Answer 3

Trophoblast
Embryoblast

Question 4

What is the trophoblast responsible for?

Answer 4

embryonic part of placenta
contacts with the endometrium of the uterus to facilitate implantation
& formation of placenta

Question 5

what is the embryoblast responsible for?

Answer 5

formation of embryo itself

Question 6

what does sperm entry into the oocyte trigger?

Answer 6

completion of meiosis II
release of cortical granules by oocyte

Question 7

what is compaction?

Answer 7

rapid mitotic division without increase in size
(confined in ZP)

Question 8

where does the embryo usually implant?

Answer 8

endometrial lining on posterior or anterior uterine wall

Question 9

name the layers the trophoblast divides into

Answer 9

cytotrophoblast
syncytiotrophoblast

Question 10

what stimulates corpus luteum? what produces it?

Answer 10

Human gonadotrophin (hCG)
syncytioblast

Question 11

what 2 layers does embryo organise into?

Answer 11

epiblast (dorsal)
hypoblast (ventral)

Question 12

which 2 cavities form? what do they form from?

Answer 12

amniotic cavity- epiblast
primitive yolk sac- hypoblast

Question 13

where is the primitive streak?

Answer 13

appears in midline at caudal end of epiblast