Embryonic development

Question 1

what is the 1st trimester?

Answer 1

embryonic stage; all organ systems form, but remain rudimentary; the biggest risk of congenital deformities occurs during this trimester

Question 2

what is the second trimester?

Answer 2

beginning of the fetal stage; maturation of all organ systems

Question 3

what does the zygote enter immediately after fertilization?

Answer 3

cleavage

Question 4

what has been produced from the cleavage process?

Answer 4

blastomeres

Question 5

what is day 0?

Answer 5

fertilization
first cleavage division

Question 6

what is day 1?

Answer 6

2-cell stage

Question 7

what is day 2?

Answer 7

4-cell stage

Question 8

what is day 3?

Answer 8

early morula
solid ball of blastomeres

Question 9

what is day 4?

Answer 9

advanced morula
reaches uterus

Question 10

What is day 6?

Answer 10

blastocyst
consists of inner cell mass and trophoblast

Question 11

what is day 7-10?

Answer 11

implantation in uterine wall

Question 12

what is inner cell mass?

Answer 12

cells destined to form embryo

Question 13

what is trophoblast?

Answer 13

the outer layer of cells
develops into supporting structures for embryo

Question 14

what is blastocele?

Answer 14

inner hollow space

Question 15

what is the epiblast?

Answer 15

blastodisc layer facing amniotic cavity

Question 16

what is hypoblast?

Answer 16

blastodisc layer facing blastocele

Question 17

what used to be the epiblast layer?

Answer 17

ectoderm

Question 18

what used to be the hypoblast layer?

Answer 18

endoderm

Question 19

what is the new layer between the epiblast and hypoblast layers?

Answer 19

mesoderm

Question 20

What contains maternal blood?

Answer 20

intervillous space

Question 21

what does the ectoderm develop into?

Answer 21

all nervous tissue

Question 22

what does the mesoderm develop into?

Answer 22

all skeletal and cardiac muscle

Question 23

what does the endoderm develop into?

Answer 23

thymus gland, thyroid gland, pancreas,digestive tract, urinary bladder,liver

Question 24

what is the amnion?

Answer 24

forms inner sac around embryo, holds the amniotic fluid in which embryo floats

Question 25

what is the chorion?

Answer 25

forms the outermost membrane around the fetus and an embryonic portion of the placenta

Question 26

what is the site of early blood formation?

Answer 26

yolk sac

Question 27

what forms part of the umbilical cord and part of the urinary bladder?

Answer 27

allantosis

Question 28

what do the umbilical arteries carry?

Answer 28

deoxygenated blood from fetus to placenta

Question 29

what is the fetal portion of the placenta?

Answer 29

chorion

Question 30

what does the umbilical vein carry?

Answer 30

carries blood rich in oxygen and nutrients to the fetus

Question 31

what conducts about half of incoming blood to vena cava, bypassing the liver?

Answer 31

Ductus venosus

Question 32

what shunts blood coming from the left atrium to the right atrium, bypassing the pulmonary circulation?

Answer 32

Foramen ovale

Question 33

what does the ductus arteriosus do?

Answer 33

further shunts blood away from the lung by conducting blood from pulmonary trunk into aorta

Question 34

what carries deoxygenated and waste-laden blood from the fetus back to the placenta?

Answer 34

umbilical arteries

Question 35

what is the foramen ovale visible as?

Answer 35

Fossa ovalis

Question 36

what does the ductus arteriosus become?

Answer 36

ligamentum arteriosum

Question 37

what do the umbilical arteries become?

Answer 37

medial umbilical ligaments

Question 38

what doe the umbilical vein become?

Answer 38

ligamentum teres (round ligament) of liver

Question 39

what does the ductus venosus become?

Answer 39

ligamentum venosum