Gastrulation

Question 1

where does the primitive streak appear

Answer 1

in the midline
caudal end of the epiblast

Question 2

what is at the cranial end of the primitive streak
what days

Answer 2

primitive streak and node
15/16

Question 3

what is the function of the primitive streak

Answer 3

alot of cell growth

Question 4

what is established by the presence of the primitive streak CC ML

Answer 4

craniocaudal and mediolateral axes

Question 5

what will the cells in the streak turn from into what

Answer 5

epithelial into a mesenchymal

Question 6

what week is the trilaminer disc formed

Answer 6

week three

Question 7

what growth factor allows for migration of the epiblast cells

Answer 7

FGF 8

Question 8

how is the notochordal process formed

Answer 8

cells migrate through the primitive pit and form a hollow midline tube extending crainailly

Question 9

what happens to the notochordal process to make it the notochord

Answer 9

it becomes flattened plate and then a solid rod

Question 10

The notochordal process fuses with what

Answer 10

endoderm

Question 11

what does the notochordal plate cells proliferate to form

Answer 11

endoderm
then it will detach

Question 12

what initiates and maintains the primitive streak

Answer 12

the TGF beta

Question 13

How does the amnion and the yolk sac communicate (nec)
what cell population are these from (pam)

Answer 13

thorugh the primitive pit called the neurnetric canal
paraxial mesoderm

Question 14

what week does neutrulation begin

Answer 14

3rd week

Question 15

at what somite level does this occur at

Answer 15

cranial 5th somite

Question 16

timeline for the neural tube formation

Answer 16

19 days neural crest
20 days - grows closer
22 - neural plate fused
24/25 - cranial neurpore closes
26/28 - caudal neurpone closes

Question 17

what is secondary neurulation
to form the medullary cord

Answer 17

mesenymal condensation of the central tail bud that will form the medullary cord

Question 18

secondary neurlation part 2

Answer 18

they will canalise to form a tube then form with the lumen of the neural tube

Question 19

what does this form

Answer 19

the sacral and coccygeal elements

Question 20

what is spina bifida

Answer 20

when the spine does not fully form

Question 21

encephalocele

Answer 21

projection of the brain tissue and the membrane that covers it it not there

Question 22

what is myelomeigoclelne

Answer 22

when the spinal cord protrudes out

Question 23

where do neural cell crst migrate to

Answer 23

lateral border of the neuroectroderm

Question 24

what happens to the neurla ectoderm

Answer 24

epithelial to mesenhymal transition then migrate to the mesoderm
to form melatogyes