Deck 2: Formation of Bilaminar Embryonic Disc and Chorionic Sac

Question 1

________ Develops as a localized thickening of hypoblast

A)Corpus luteum
B)Zona pellucida
C)Prechordal plate
D)Ectopic implantation
E)Chorionic sac

Answer 1

C
The prechordal plate indicates the future cranial end of the embryo and the future site of the mouth.It is a circular area of endoderm that is firmly adherent to the overlying embryonic epiblast.It is an important landmark in the early embryo and serves as an organizer of the cranial region of the embryo.

Question 2

________ Extraembryonic coelom

A)A
B)B
C)C
D)D
E)E

Answer 2

E
The extraembryonic coelom,part of which is indicated in the diagram,consists of isolated spaces in the extraembryonic mesoderm.Later,these spaces coalesce to form a single,large cavity.

Question 3

________ Cytotrophoblast

A)A
B)B
C)C
D)D
E)E

Answer 3

D
The cytotrophoblast is the inner layer of the trophoblast.It gives rise to (1)the outer layer of trophoblast (syncytiotrophoblast), (2)amnioblasts (cells that form the amnion),and (3)part of the extraembryonic mesoderm.The cytotrophoblast,as the prefix cyto- implies,is a cellular layer.

Question 4

________ Surrounds embryo,amnion,and umbilical vesicle (yolk sac)

A)Corpus luteum
B)Zona pellucida
C)Prechordal plate
D)Ectopic implantation
E)Chorionic sac

Question 5

________ Site of the decidual reaction

A)A
B)B
C)C
D)D
E)E

Question 6

________ Epiblast forms its floor

A)A
B)B
C)C
D)D
E)E

Question 7

________ Most common site of an ectopic pregnancy

A)A
B)B
C)C
D)D
E)E

Question 8

________ Abdominal pregnancy

A)A
B)B
C)C
D)D
E)E

Question 9

________ Lacunar network

A)A
B)B
C)C
D)D
E)E

Question 10

________ Ovarian pregnancy

A)A
B)B
C)C
D)D
E)E

Question 11

________ Develops from a ruptured ovarian follicle

A)Corpus luteum
B)Zona pellucida
C)Prechordal plate
D)Ectopic implantation
E)Chorionic sac

Question 12

________ Usual site of implantation

A)A
B)B
C)C
D)D
E)E

Question 13

________ Derived from cytotrophoblast

A)A
B)B
C)C
D)D
E)E

Question 14

________ Ventral layer of embryonic disc

A)A
B)B
C)C
D)D
E)E

Question 15

________ Implantation at internal os

A)A
B)B
C)C
D)D
E)E

Question 16

________ Lies between the cytotrophoblast and the epiblast

A)A
B)B
C)C
D)D
E)E