Intro to Basic Development

Question 1

Week 1-8

Answer 1

embryonic period

Question 2

Week 9-36

Answer 2

fetal period

Question 3

Week 23

Answer 3

embryo is viable

Question 4

ovum breaks out of perioteal membranes

Answer 4

mittlescherz

Question 5

what sweeps ovum into tube

Answer 5

scary fallopian fimbriae

Question 6

oocytes are viable for

Answer 6

24 hours after ovulation

Question 7

sperms are viable

Answer 7

For 3 days!

Question 8

reaction of uterine lumen to fertilized egg implanting

Answer 8

decidual reaction

Question 9

yolk sac is on which side?

Answer 9

ventral

Question 10

amniotic cavity is on which side?

Answer 10

dorsal

Question 11

primitive streak starts

Answer 11

caudal and grows toward head

Question 12

cells streaming from the primitive streak start which layer?

Answer 12

middle layer!

Question 13

ectoderm

Answer 13

skin, nervous

Question 14

mesoderm

Answer 14

connective, GU

Question 15

endoderm

Answer 15

gut

Question 16

extension of primitive streak rostrally is the origin of

Answer 16

notochord

Question 17

notochord is

Answer 17

condensation of cells that induces the overlying ectoderm to differentiate into nervous system

Question 18

lateral ectoderm becomes

Answer 18

skin, jerk.

Question 19

ectoderm invaginates and pinches off to form

Answer 19

neural tube

Question 20

neural crest

Answer 20

origin of nervous system,cells that delaminate and migrate fromadjacent to the neural tube

Question 21

neural tube closure first occurs

Answer 21

in future neck, or else spina bifida, detectable by leak of CSF into amniotic fluid

Question 22

paraxial mesoderm gives rise to

Answer 22

somites (skeleton, muscle)

Question 23

intermediate mesoderm gives rise to

Answer 23

GU system

Question 24

lateral mesoderm, 2 layers

Answer 24

top (next to ectoderm), bottom (next to endoderm)

Question 25

top mesoderm becomes

Answer 25

body wall

Question 26

bottom mesoderm becomes

Answer 26

visceral wall: internal around the gut

Question 27

intraembryonic coelum

Answer 27

space between top and bottom mesoderm, becomes body cavities

Question 28

blood island and heart form

Answer 28

via vasculogenesis in interembryonic coelum

Question 29

where does the heart form

Answer 29

all the way anterior! (that's in the head!)

Question 30

at four weeks: folding

Answer 30

neural tube grows faster than other tissues and causes head and tail fold

Question 31

what positions heart and connecting stalk (and allantois) to position on the ventral surface

Answer 31

neural tube folding over endoderm

Question 32

at four weeks: yolk sac becomes

Answer 32

foregut, midgut, hind gut.

Question 33

what creates the allantois?

Answer 33

tail fold bringing amniotic cavity into the embryo

Question 34

does lateral folding happen at 4 weeks?

Answer 34

yes.

Question 35

how many umbilical arteries?

Answer 35

two!

Question 36

how many umbilical veins?

Answer 36

one!

Question 37

Intra-embryonic coelum folding creates

Answer 37

future pericardial cavity, accompanying heart to ventral surface of the embryo.

Question 38

dorsal aorta

Answer 38

the six precursors to the great vessels. Formed in pharyngeal folds

Question 39

embryonic blood flow

Answer 39

placenta> umbilical vein> liver> inferior vena cava> right heart> foramen ovale> left atrium> aorta> internal iliacs> umbilical artery> bladder> placenta

Question 40

umbilical artery

Answer 40

has LOW O2

Question 41

umbilical vein

Answer 41

has high O2

Question 42

most of liver

Answer 42

is mostly bypassed via ductus venosum

Question 43

blood in inferior vena cava

Answer 43

mixes with venous return

Question 44

foramen ovale

Answer 44

for bypassing the lungs!

Question 45

embryonic pulmonary blood flow

Answer 45

right heart> pulmonary artery> ductus arteriosus> aorta

Question 46

lung pressure is ____because lung is not functional

Answer 46

high

Question 47

at birth, right heart pressure

Answer 47

falls due to lack of blood in the umbilical vein

Question 48

at birth, foramen ovale

Answer 48

closes (due to higher pressure on the left), forcing right heart blood into lungs

Question 49

at birth, ductus venosus

Answer 49

closes, becomes ligamentum venosum

Question 50

at birth, ductus arteriosis

Answer 50

closes, becomes ligamentum arteriosum

Question 51

at birth, umbilical arteries become

Answer 51

blood supply to the bladder

Question 52

By 8 weeks

Answer 52

inch long embryo with all systems formed