Embryology Basic Body Plan

Question 0

four major steps in week one of development

Answer 0

fertilization
cleavage
blastocyst formation
implantation

Question 1

fertilization occurs in

Answer 1

the ampulla of the uterine tube

Question 2

resultant cells of cleavage are called

Answer 2

blastomeres

Question 3

blastomeres are totipotent up to

Answer 3

the 4-8 cell stage

Question 4

16-32 cell stage of cleavage is called

Answer 4

morula

Question 5

2 processes that turn a morula into a blastocyst

Answer 5

compaction and cavitation

Question 6

cleavage occurs between (time)

Answer 6

1-4 days

Question 7

inner cell mass of blastocyst: name, and becomes

Answer 7

embryoblast, becomes embryo

Question 8

outer cell mass of blastocyst, name and becomes

Answer 8

trophoblast, becomes fetal portion of placenta

Question 9

cell type in embryoblast

Answer 9

pluripotent stem cells

Question 10

morula compacts and cavitates to become _____ at _____ (time)

Answer 10

blastocyst, 4.5-5 days

Question 11

blastocyst implants in uterine wall by (time)

Answer 11

6-7 days

Question 12

ruptured follicle becomes

Answer 12

corpus luteum

Question 13

corpus luteum produces

Answer 13

progesterone

Question 14

progesterone does what to the uterus

Answer 14

enter secretory phase

Question 15

which cells of the blastocyst invade the uterine epithelium

Answer 15

trophoblasts

Question 16

what hormone is produced by trophoblasts as they invade uterine epithelium?

Answer 16

human Chorionic Gonadotropin (hCG)

Question 17

Trophoblast during week two

Answer 17

differentiates into syncytiotrophoblast (outer layer) and cytotrophoblast (inner layer)

Question 18

embryoblast during week two

Answer 18

differentiates into epiblast and hypoblast

Question 19

epiblast during week two

Answer 19

secretes fluid to form the amniotic cavity

Question 20

hypoblast in week 2

Answer 20

line blastocyst cavity, form primitive yolk sac

Question 21

trophoblast lacunae do what

Answer 21

connect to sinusoids in endometrial stroma

Question 22

embryo is embedded in endometrial stroma by (time)

Answer 22

12 days

Question 23

new cavity formed by hypoblast in week two

Answer 23

chorionic cavity

Question 24

lining of chorionic cavity

Answer 24

extraembryonic mesoserm

Question 25

dizygotic twins constitute ____% of twinning cases

Answer 25

70

Question 26

monozygotic twins constitute ____% of twinning cases

Answer 26

30

Question 27

monozygotic twin spits at early blastocyst

Answer 27

separate amnion, common chorion and placenta

Question 28

monozygotic twins split at late blastocyst

Answer 28

common chorion, amnion and placenta

Question 29

pregnancy without an embryo

Answer 29

hyatidiform mole

Question 30

lab and clinical signs of hyatidiform mole

Answer 30

high hCG, vaginal bleeding, large uterus

Question 31

"It is not birth, marriage, or death, but ________, which is truly the most important time in your life." Lewis Wolpert

Answer 31

gastrulation

Question 32

gastrulation occurs in (time)

Answer 32

week 3

Question 33

gastrulation establishes _______ and defines ________

Answer 33

3 germ layers of the embryo | body axes

Question 34

during gastrulation, epiblast cells

Answer 34

invaginate at the caudal midline (primitive streak) and migrate to replace hypoblast

Question 35

replacement of hypoblast cells with epiblast cells froms

Answer 35

endoderm

Question 36

epiblast cells that migrate between hypoblast and epiblast form

Answer 36

the mesoderm

Question 37

after gastrulation, the epiblast is called

Answer 37

the ectoderm

Question 38

ectoderm becomes

Answer 38

nervous system, epidermis, sensory epithelium of nose, ear, and eye

Question 39

mesoderm becomes

Answer 39

muscle, cartilage, bone, connective tissue, parts of kidney and gonads

Question 40

endoderm becomes

Answer 40

epithelium of gut, epithelium of respiratory system

Question 41

caudal dysgenisis aka

Answer 41

sirenomelia

Question 42

caudal dysgenesis caused by

Answer 42

abnormal gastrulation, migration is disturbed, insufficient caudal mesoderm

Question 43

period of maximal sensitivity to abnormal development

Answer 43

3-8 weeks