Lecture 4: Embryogenesis

Question 1

What field studies development between fertilization and birth?

Answer 1

embryology

Question 2

What field studies embryonic and other developmental processes such as stem cell biology and regeneration?

Answer 2

developmental biology

Question 3

What % of embryos are spontaneously aborted?

Answer 3

50%

Question 4

what % of live born children have a birth defect?

Answer 4

3-6%

Question 5

what % of births are premature in the USA? Is this higher or lower than the % of premature births in other developed countries?

Answer 5

~12%

higher

Question 6

what are the two leading causes of infant mortality?

Answer 6

premature births

birth defects

Question 7

Weeks _____ of human pregnancy are known as embryogenesis (also called organogenesis), when_______ are established

Answer 7

1-8

embryogenesis

Question 8

What are organ primordia?

Answer 8

organs in earliest recognizable stage of development

Question 9

The embryonic period is followed by the ______ of continued _______ and ______

Answer 9

fetal period
differentiation
growth

Question 10

What are Carnegie Stages of embryogenesis based on? What are they not based on?

Answer 10

based on external features

not based on chronological age nor size

Question 11

How many Carnegie stages are there?

Answer 11

23

Question 12

What is postovulatory age refer to? what terms does it replace?

Answer 12

maturity of embryo - length of time since last ovulation before pregnancy
better than gestation, pregnancy, conception

Question 13

In the ____ week of embryogenesis, the zygote undergoes division to become a _____ and then a _______

Answer 13

first
morula
blastocyst

Question 14

What structure implants into the uterine wall?

Answer 14

blastocyst

Question 15

The oocyte is fertilized in the ______ region of the ________

Answer 15

ampullary

uterine tube

Question 16

what ploidy is the zygote?

Answer 16

diploid

Question 17

how does the female anatomy help the sperm reach the oocyte?

Answer 17

muscular contractions of the uterus and uterine tube toward the ovary

Question 18

without fertilization, the oocyte degenerates _____ after ovulation

Answer 18

24 hours

Question 19

what kind of division do the oocyte and sperm undergo after fertilization?

Answer 19

mitotic

Question 20

during cleavage mitotic divisions of embryogenesis, cells are known as _______

Answer 20

blastomeres

Question 21

during cleavage mitotic divisions of embryogenesis, ______ segregates ______ fomr ______

Answer 21

compaction
inner cells
outer cells

Question 22

____ days after fertilization, the ____-cell morula is formed

Answer 22

3 days

16 cell

Question 23

How many hours post-fertilization...
2 cell stage
4 cell stage
16 cell stage
late morula stage

Answer 23

2 cell stage - 30hrs
4 cell stage - 40hrs
16 cell stage - 3 days
late morula stage - 4 days

Question 24

What stabilizes the cells during compaction of embryogenesis?

Answer 24

tight junctions between outer cells

seals off inner cells

Question 25

What does the blastocyst turn into?

Answer 25

Inner Cell Mass

Trophoblast

Question 26

What does the inner cell mass turn into?

Answer 26

Amnionic ectoderm

Embryonic epiblast

Question 27

What does the amniotic ectoderm turn into?

Answer 27

Nothing

Question 28

What does the embryonic epiblast turn into?

Answer 28

Embryonic ectoderm

Primitive streak

Question 29

What does the primitive streak turn into?

Answer 29

Embryonic endoderm

Embryonic Mesoderm

Question 30

What do the Embryonic Ectoderm, Endoderm, and Mesoderm turn into?

Answer 30

Nothing

Question 31

What does the Hypoblast turn into?

Answer 31

Extraembryonic endoderm

Question 32

What does the extraembryonic endoderm turn into?

Answer 32

Yolk sac

Question 33

The yolk sac and embryonic mesoderm combine to form _______

Answer 33

extraembryonic mesoderm

Question 34

What does the trophoblast turn into?

Answer 34

Cytotrophoblast

Question 35

What does the cytotrophoblast turn into?

Answer 35

Syncytiotrophoblast