Pre-Embryonic Period

Question 1

cleavage

Answer 1

zygote undergoing mitotic divisions

Question 2

morula

Answer 2

16-cell stage (hasn’t reached uterus)

Question 3

blastocyst

Answer 3

morula enters uterine cavity
contains fluid-filled blastocyst cavity in center

Question 4

trophoblast (component of blastocyst)

Answer 4

outer ring of cells that will develop into the chorion (superficial)

Question 5

embryoblast (component of trophoblast)

Answer 5

cluster of tightly packed cells inside one side of the blastocyst that will form the embryo

Question 6

pluripotent

Answer 6

can differentiate into any cell type in the human body (stem cells) END OF WEEK 1

Question 7

What day does the blastocyst completely burrow into uterine wall?

Answer 7

day 9

Question 8

bilaminar germinal disc

Answer 8

day 8, embryoblast differentiate into 2 distinct types, hypoblast and epiblast

Question 9

hypoblast (below)

Answer 9

layer of small cuboidal cells facing the blastocyst cavity

Question 10

epiblast

Answer 10

layer of columnar cells deep to hypoblast

Question 11

What components are involved in the formation of the extra-embryonic membranes?

Answer 11

bilaminar germinal disc and trophoblast produce 3 extraembryonic membranes
yolk sac
amnion
chorion

Question 12

yolk sac

Answer 12

serves as a site for early blood cell and vessel formation (cavity attached to hypoblast)

Question 13

amnion (on top of yolk sac)

Answer 13

thin layer of cells that forms above and is derived from the epiblast (protect embryo and fetus)

Question 14

chorion (previously trophoblast)

Answer 14

outermost membrane responsible for formation of the placenta

Question 15

What is the purpose of the development of the placenta?

Answer 15

serves as an interface between embryo/fetus and mother

Question 16

What are the main functions of the placenta?

Answer 16

exchange of nutrients, waste products, maternal antibodies and respiratory gases
production of estrogen and progesterone to maintain uterine lining