B8-031 Embryogenesis

Question 1

gastrulation begins with the formation of the

Answer 1

primitive streak

Question 2

formation of trilaminar disc from epiblast occurs in week […]

Answer 2

3

Question 3

layers formed during gastrulation [3]

Answer 3

endoderm
mesoderm
ectoderm

Question 4

forms the extraembryonic endoderm and mesoderm

Answer 4

hypoblast

Question 5

[…] cells are among the first to ingress from the primitive streak

Answer 5

pre-notochordal cells

Question 6

acts with the primitive nodes as a second signaling regions in the head region

Answer 6

anterior visceral endoderm

Question 7

expresses genes essential for head formation

inhibits the formation of the primitive streak in the head

Answer 7

anterior visceral endoderm

AVE

Question 8

the anterior/cranial end of the embryo is established [before/after] gastrulation

Answer 8

before

Question 9

dorsalizing molecules [4]

Answer 9

chordin
goosecoid
noggin
follistatin

Question 10

dosalizing molecules dorsalize the cranial mesoderm to form [3]

Answer 10

head structures
notochord
paraxial mesoderm

Question 11

antagonizes the dorsalizers

ventralizes mesoderm to form intermediate and lateral plate mesoderm

Answer 11

BMP 4

Question 12

dorsalizes mesoderm in middle and caudal embryo to form paraxial mesoderm somites

Answer 12

brachyury T

Question 13

what causes sirenomelia?

Answer 13

absence of Brachyury T

results in shortening of axis and fusion of limb buds

Question 14

notochord forms ventral to

Answer 14

neural plate

Question 15

notochord arises from mesoderm and induces the overlying ectoderm to form […]

Answer 15

neural plate

(notochord secrete the dorsalizing molecule to induce the ectoderm)

Question 16

notochord and primitive streak [do/do not] overlap

Answer 16

do not

Question 17

FGF8 establishes expression of nodal on the left, but then […] represses left-sideness genes on RIGHT

Answer 17

SHH

(results in right handedness)

Question 18

abnormalities in cilia proteins lead to […] defects

Answer 18

laterality

(cilia set up directional fluid flow in the primitive node that moves the signaling molecules in specific patterns)

Question 19

situs inversus and primary ciliary dyskinesia are due to defects in

Answer 19

cilia proteins

Question 20

overexpression of […] results in conjoined twin phenotype

Answer 20

goosecoid

Question 21

when is the embryo most sensitive to teratogenic insult

Answer 21

week 3

Question 22

merged forebrain occurring due to high doses of alcohol consumption

Answer 22

holoprosencephaly

Question 23

failure of eye fields to separate properly

Answer 23

synopthalmia

Question 24

de novo formation of the endothelial tubes from precursor cells

Answer 24

vasculogenesis

Question 25

sprouting of endothelial lined vascular tubes off existing vessels

Answer 25

angiogenesis

Question 26

blood vessels form from [...] mesoderm

Answer 26

LPM

Question 27

unbalanced blood supply between twins in shared placenta results in a net flow from one twin to the other

Answer 27

twin-twin transfusion syndrome

Question 28

in twin-twin transfusion syndrome, the [...] twin will present with hypovolemia and oligohydramnios

Answer 28

donor

Question 29

in twin-twin transfusion syndrome, the [...] twin will present with hypervolemia and polyhydramnios

Answer 29

recipient

Question 30

congenital vascular malformation that is: common often occurs in craniofacial regions may disappear over time

Answer 30

capillary hemangiomas

Question 31

congenital vascular malformation that is: less common gets larger and darker over time skin thickens

Answer 31

port-wine stains

Question 32

defects of ventral body wall [4]

Answer 32

ectopia cordis gastroschisis cloacal exstrophy bladder exstrophy

Question 33

defects of ventral body wall are caused by

Answer 33

failure to close after lateral folding

Question 34

the [...] layer of the bilaminar germ disc contributes to cells that invaginate during gastrulation

Answer 34

epiblast

Question 35

the [...] consists of multinucleated cells

Answer 35

syncytiotrophoblast

Question 36

the [...] consists of small cuboidal cells

Answer 36

hypoblast

Question 37

differentiate from the trophoblast [2]

Answer 37

syncytiotrophoblast cytotrophoblast

Question 38

the inner cell mass hallows to form the [...] cavity

Answer 38

blastocyst

Question 39

gastrulation starts with the formation of the [..] on the surface of the epiblast

Answer 39

primitive streak

Question 40

dorsalized ectoderm that forms the neural tube

Answer 40

neural plate

Question 41

notochord induces overlying [...] to form

Answer 41

neural plate

Question 42

the [...] is at the cranial end of the primitive streak

Answer 42

primitive node

Question 43

the primitive streak first extends [...]

Answer 43

cranially (those cells form the primitive node)

Question 44

forms the non-invaginated epiblast

Answer 44

ectoderm

Question 45

fusion of lower limbs and vertebral abnormalities

Answer 45

sirenomelia

Question 46

transposition of the viscera in the thorax/abdomen

Answer 46

situs inversus

Question 47

defects of cilia on node cells leads to [...] defects

Answer 47

laterality

Question 48

mesoderm is ventralized by

Answer 48

BMP4

Question 49

nodal is expressed on the embryonic [...] side

Answer 49

left

Question 50

head genes are expressed in the

Answer 50

anterior visceral endoderm

Question 51

responsible for dorsalization of the cranial mesoderm

Answer 51

chordin

Question 52

lateral folding promotes formation of [4]

Answer 52

cardiac tube gut tube body cavities **ventral body wall**

Question 53

initial site of hematopoiesis during prenatal development

Answer 53

extraembryonic blood islands

Question 54

hemangioblasts are derived from what germ layer?

Answer 54

mesoderm

Question 55

hemangioblasts form [2]

Answer 55

hematopoietic stem cells angioblasts

Question 56

blood islands arise during the process of

Answer 56

vasculogenesis

Question 57

epidermis is derived from

Answer 57

ectoderm

Question 58

foregut lining is derived from

Answer 58

endoderm

Question 59

dermis of the back is derived from

Answer 59

paraxial mesoderm

Question 60

heart is derived from

Answer 60

splanchnic lateral plate mesoderm

Question 61

urogenital system arises from

Answer 61

intermediate mesoderm

Question 62

the embryonic period encompasses weeks [...] of development

Answer 62

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