Second Week Of Development

Question 1

Implantation occurs on

Answer 1

6th -7th day of fertilisation

Question 2

Implantation is completed on

Answer 2

2nd week

Question 3

Hypoblast is also called

Answer 3

Primitive endoderm

Question 4

Hypoblast contributes to formation of

Answer 4

Roof of primary yolk sac

Question 5

Epiblast / primitive ectoderm consists of ——- cells

Answer 5

Columnar

Question 6

The first germ layer to be formed is

Answer 6

Hypoblast

Question 7

Amniotic cavity is a space between ————- below and ————- above

Answer 7

Epiblast

Trophoblast

Question 8

Roof of amniotic cavity has ———- cells derived from the trophoblast while it’s floor is formed by epiblast

Answer 8

Amniogenic cells

Question 9

Flattened cells of ——— spread and line the inside of blastocystic cavity ( lining of cells- heusers membrane)
Cavity —- primary yolk sac

Answer 9

Hypoblast

Question 10

The cells of ———— give origin to extraembryonic mesoderm

Answer 10

Trophoblast

Question 11

The cells of extra embryonic mesoderm separate the walls of ——— from ——-

Answer 11

Amniotic cavity ; trophoblast

Question 12

Small cavities in extraembryonic mesoderm—fuse— one large cavity called —

Answer 12

Extraembryonic coelom

Question 13

The part lining the inside of the trophoblast and the outside of the amniotic cavity is called

Answer 13

Parietal/somatopleuric mesoderm

Chorionic plate

Question 14

The part lining the outside of yolk sac is called

Answer 14

Visceral or splanchnopleuric extra embryonic mesoderm

Question 15

The extraembryonic coelom does not extend into that part of the extraembryonic mesoderm which attaches the wall of the amniotic cavity to the ———

Answer 15

Trophoblast

Question 16

The unsplit part of mesoderm forms a structure known as

Answer 16

Connecting stalk

Question 17

Chorion is formed by

Answer 17

Parietal/ somatopleuric extraembryonic mesoderm on Inside

Trophoblast on outside

Question 18

Yolk sac becomes much smaller so it is called

Answer 18

Secondary yolk sac

Question 19

The cells of yolk sac are no longer flattened but become ———-

Answer 19

Cubical

Question 20

The wall of the yolk sac is first site for formation of

Answer 20

Blood

Question 21

Yolk sac forms endodermal lining of

Answer 21

GI tract and respiratory tract

Question 22

Epiblast has ———- cells

Hypoblast has ——— cells

Answer 22

Columnar

Cuboidal

Question 23

Cubical cells of hypoblast become columnar. This area is called

Answer 23

Prochordal plate

Question 24

The first embryonic membrane is

Answer 24

Trophoblast

Question 25

Trophoblast are precursor cells of ———-

Answer 25

Human placenta

Question 26

Differentiation of trophoblast is essential for the formation of

Answer 26

Chorionic villi

Question 27

Cells nearest to decidua lose their cell boundaries and form a continuous sheet of cytoplasm with many nuclei (syncytium)
This layer of trophoblast is called

Answer 27

Syncytiotrophoblast / plasmodiotrophoblast

Question 28

Cells of the trophoblast deep to syncytium retain their walls and form a layer called

Answer 28

Cytotrophoblast / langerhans layer

Question 29

Langerhans layer (cuboidal cells) with a clear outline rests on

Answer 29

Extraembryonic mesoderm

Question 30

Chorionic villi is formed by

Answer 30

Syncytiotrophoblast
Cytotrophoblast
Somatopleuric layer of extraembryonic mesoderm

Question 31

What is chorion

Answer 31

The cellular outermost extraembryonic membrane composed of trophoblast lined with extra embryonic somatopleuric mesoderm