2nd week

Question 1

Inner cell mass forms:

Answer 1

Epiblast (columnar cells on dorsal side)

Hypoblast (cuboidal cells on ventral side)

Question 2

Epiblast forms:

Answer 2

amnion and encloses cavity lined with amniogenic cells

Question 3

Hypoblast forms:

Answer 3

forms exocoelomic membrane and encloses primary yolk sac lined by flattened squamous cells

Question 4

USG on 2nd week shows:

Answer 4

Double bleb sign

Question 5

outer cell mass (trophoblast) forms:

Answer 5

cytotrophoblast (single nucleated and well-defined membrane)

syncytotrophoblast (multinucleated and no well-defined membrane)

Question 6

Outer cell mass divides into cytotrophoblast and syncytotrophoblast on:

Answer 6

8th day

Question 7

Extra-embryonic membrane is derived from:

Answer 7

primary yolk sac? epiblast> hypoblast

Question 8

Assay of hCG:

Answer 8

on 8th day: maternal blood

on 10th day: maternal urine

Question 9

Low hCG:

Answer 9

1) ectopic pregnancy

2) spontaneous pregnancy

Question 10

High hCG:

Answer 10

1) multiple pregnancy
2) molar pregnancy
3) gestational trophoblastic neoplasia

Question 11

Chorion is formed by 3 structures:

Answer 11

EEM, cytotrophoblast, syncytotrophoblast

Question 12

Primary chorionic villi:

Answer 12

cytotrophoblast projects into syncytotrophoblast

Question 13

Uteroplacental circulation established by:

Answer 13

day 15

Question 14

Fetoplacental circulation establised by:

Answer 14

day 17> day 22

Question 15

First system to develop:

Answer 15

CVS (formation of heart tubes)

Question 16

EEM divided into:

Answer 16

Somatic/ parietal layer and splanchnopleuric layer by cavity in the EEM

Question 17

secondary chorionic villi

Answer 17

EEM projects into primary villi

1) EEM
2) Cytotrophoblast
3) Syncytotrophoblast

Question 18

Secondary chorionic villi formed on:

Answer 18

day 12

Question 19

primary chorionic villi formed on:

Answer 19

day 12

Question 20

Undivided part of EEM forms:

Answer 20

connecting stalk/ umbilicus