Embryology

Question 1

Mitosis

Answer 1

yields 2 diploid cells

Question 2

Meiosis

Answer 2

yields 4 haploid cells

Females- 1 oocyte and 3 polar bodies

Question 3

Zygote

Answer 3

Day 0
diploid
sperm fused with egg

Question 4

Cleavage

Answer 4

Day 1

zygote divides into 2 cells but stays the same size

Question 5

Compaction

Answer 5

Day 3

8 cells fuse together

Question 6

Morula

Answer 6

Day 4

16-32 cells

Question 7

Embryoblast

Answer 7

central blastomeres during compaction

forms embryo placenta

Question 8

Trophoblast

Answer 8

peripheral blastomeres during compaction

forms placenta

Question 9

Blastocoel

Answer 9

cavity w/in morula that stores fluid

Question 10

Blastocyst

Answer 10

Day 5
embryoblast cells compact at one side and trophoblast cells form layer around it
has embryonic pole and abembryonic pole

Question 11

Decidual Cells

Answer 11

react to implantation and progesterone

Question 12

Epiblast

Answer 12

external/ upper layer of bilaminar blastoderm

Question 13

Hypoblast

Answer 13

Internal/ lower layer of bilaminar blastoderm

Question 14

Amniotic Cavity

Answer 14

Day 8

collects fluid between epiblast cells

Question 15

Heuser’s Membrane

Answer 15

Day 9

migration of hypoblast cells

Question 16

Primary Yolk Sac

Answer 16

formed by Heuser’s Membrane

Question 17

Chorionic Cavity

Answer 17

Days 11-12

extraembryonic mesoderm splits into 2 layers

Question 18

Definitive Yolk Sac

Answer 18

Days 12-13
2nd migration of hypoblast cells
causes primary yolk sac to break up

Question 19

Extraembryonic Mesoderm

Answer 19

outer layer of yolk sac

major site of hematopoiesis

Question 20

Parts of Ectoderm and Mesoderm

Answer 20

Amnion and Chorion

Question 21

Parts of Endoderm and Mesoderm

Answer 21

Yolk Sac